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An eco-friendly and facile in-situ polymerization method was used to develop template free acid-etched graphitic carbon nitride (TGCN) nanosheets with optimized PANI nanofibers. PANI nanofibers grown on TGCN nanosheets offer large surface area, high porosity and unique charge transfer properties. The rapid agglomeration of TGCN nanosheets throughout electrochemical measurements lowers the specific capacitance due to its reduced shelf life which was overcome by the incorporation of a suitable polymer (PANI) as a spacer. Herein, We report the comparative electrochemical performance of TGCN/PANI nanocomposites as a function of morphology, composition, surface area and pore size study was obtained using X-Ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), X-Ray Photoelectron Spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) N 2 adsorption-desorption. Herein, we prepared TGCN/PANI nanocomposites, which are also optimized to act as a highly efficient electrode nanocomposite for high-performance supercapacitor applications. The optimized TGCN/PANI (TCP50) nanocomposite showed a high specific capacitance of 298.31 F/g at a scan rate of 0.02 V s-1 and long cycling stability with low capacitance loss after 5000 cycles as well as low leakage current and self-discharge. At a power density of 400 W/kg, TCP50 electrode exhibits superior energy density of 33.57 Wh/kg. • PANI nanofibers synthesized on the surface of TGCN. • Optimized TGCN/PANI electrode showed enhanced (298.31 F/g) specific capacitance. • TCP50 exhibit superior energy density of 33.57 Wh/kg at 400 W/kg of power density. • TCP50 shows highest coulombic efficiency (∼above 80%) and capacitance retention (∼above 75%) after 5000 cycles. • The leakage current and self-discharge test were explored for practical application. [ABSTRACT FROM AUTHOR]

A detailed structural study involving in situ glancing angle x-ray diffraction (GAXRD) analysis carried out on Pd nanoparticle and thin film samples at hydrogen concentrations of 2%, 5%, and 10% over temperature ranging from -100 to 55 °C and hydrogen pressures ranging from 250 to 1000 mbars is reported. Variation in the lattice constant has been interpreted in terms of hydrogen content in α and β PdHx phases, and decrease in XRD peak intensity has been interpreted in terms of hydrogen induced degradation in crystalline quality and temperature induced lattice disorder. It is observed that Pd–H interaction is strongly influenced by the temperature and pressure dependences of physisorption, chemisorption, and diffusion. These results show that the increased surface area, interparticle gaps, and electronic enhancement result in enhanced Pd–H interaction in case of nanoparticles. In addition, the presence of single β phase and lower crystallinity degradation is observed in the case of Pd nanoparticles in comparison to thin films. The above mentioned differences between nanoparticles and thin films are more pronounced at lower temperatures due to the increased presence of subsurface sites. [ABSTRACT FROM AUTHOR]

• Constructed a highly sensitive Pd nano /MoS 2 based interface for detection of Ach. • Facile preparation of Pd nano /MoS 2 nanocomposite modified Au electrode. • Co-immobilization of AchE and Cho enzymes over nanocomposite modified Au electrode. • The linear response from 1.0 nM to 1000 μM for Ach with a detection limit of 1.0 nM. • Improved analytical performance of sensor with feasibility in real samples analysis. Acetylcholine (ACh) present inside the brain has ability to alter neuronal activation, influencing transmission of synapse by inducing neurons causing the enhancement in the ability of neuronal networks inside the brain. In result, ACh modifies the response of internal and external environment and perform function as a neuromodulator. This empowers the plan of a sensor particular for ACh that is effectively brought into biological frameworks. The work described here, an acetylcholinesterase (AChe) based sensor which is the most promising tool for analysis of neuromodulator level in biological samples. The prepared biosensor interface is based on co-immobilization of the AChe and choline oxidase (Cho) onto palladium nanoparticles (Pd nano) adsorbed over molybdenum disulfide (MoS 2) nanostructures electrodeposited on the surface of gold electrode (Au-ET). The sensor had excellent linear range of 1.0 nM to 10 mM with 1.0 nM as limit of detection. The novel AChe-Cho/Pd nano /MoS 2 @Au-ET shows a tremendous potential for applications in medical research and clinical diagnosis. The novel biosensor formed has good accuracy, precision and reliability hence, it might provide a new outlook for the detection and recognition of ACh in real serum samples. [ABSTRACT FROM AUTHOR]

Abstract MoS 2 -PANI hybrid structure were synthesized by insitu polymerization of hydrothermally synthesized MoS 2 nanosheets with PANI for its application in photodetectors. Field-Emission Scanning Electron Microscopy (FESEM), High-Resolution Transmission Electron Microscopy (HRTEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV–vis spectroscopy delete were performed to characterize the synthesized sample. The optical sensor of MoS 2 -PANI hybrid structure were fabricated and altogether studied using laser excitation wavelengths (λ ex): 635 nm (red), 785 nm (infra-red) and 1064 nm (near infra-red). The evaluated value of photoresponsivity of hybrid structure is quite high compared to the previously reported MoS 2 nanosheets based optical sensor. At 785 nm, maximum photoresponsivity of 25 A/W is observed at fixed power density of 1.4 mW/mm2. The photoresponsive characteristics of MoS 2 -PANI hybrid structure were examined as a function of optical power density. Highlights • MoS 2 - PANI hybrid structure synthesized by in-situ polymerization of hydrothermally synthesized MoS 2 nanosheets. • Hybrid structure characterized by XRD, SEM, TEM, FTIR and UV–Vis spectroscopy. • MoS 2 -PANI based exceedingly photoresponsive and reproducible broadband photodetector. • System holds potential for commercial scale creation. [ABSTRACT FROM AUTHOR]

In the present work, MoS 2 nanosheets were synthesized by a hydrothermal method for optical sensing application. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Raman and UV–vis spectroscopy were carried out to characterize the synthesized MoS 2 nanosheets. SEM and TEM images showed the morphology of ultrathin nanosheets of MoS 2 . Optical sensor of MoS 2 nanosheets was fabricated and thoroughly studied using various laser excitation wavelengths (λe x ): 440 nm (indigo); 460 nm (blue); 550 nm (green); 570 nm (yellow); 635 nm (red) and 785 nm (infra-red). The excellent photoresponsivity was observed in the visible range and maximum was found to be 23.8 μA/W for λe x: 635 nm (red illumination). The mechanism for photoresponse was proposed and correlated with the absorption spectroscopy. The response and recovery times for 635 nm were 2.5 and 3.2 s, respectively. The photoresponsive characteristics of MoS 2  nanosheets were also explored as a function of optical power density. [ABSTRACT FROM AUTHOR]

The photo-antimicrobial and photocatalytic performance of ZnO nanorods as a function of aspect ratio are presented. The antibacterial activity of the synthesized ZnO nanorod samples against Gram-negative and Gram-positive bacteria ( Staphylococcus aureus and Escherichia coli, respectively) was determined by shake flask method with respect to time. ZnO nanorods with high aspect ratio showed superior antimicrobial and photocatalytic activity. These results are supported by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence, and Brunauer-Emmett-Teller (BET) studies. Degradation of methylene blue dye as model organic pollutant was used to assess their photocatalytic activity. Pseudo-first-order rate kinetics was used to calculate the photocatalytic reaction rate constant. The mechanisms for both antimicrobial and photocatalytic activity are elucidated. [ABSTRACT FROM AUTHOR]

For better utilization of solar spectrum and complete redox of water for water splitting applications, it is required to have a semiconductor which is photoactive in visible region. In this study, we report theoretical and experimental investigations on morphological and opto-electronic modifications induced in α-Bi 2 O 3 due to Selenium (Se) doping tested for photoelectrochemical (PEC) & photocatalytic properties. Density Functional Theory (DFT) calculations revealed band gap reduction and direct to indirect transitions in Se-doped α-Bi 2 O 3. This reduction in band gap is attributed to hybridization of Se p & Bi s in valence band and Se d & Bi p orbital in conduction band. To support this finding experimentally, we synthesized Se-doped α-Bi 2 O 3 using simple chemical precipitation method and measured its band gap using photoluminescence and UV–Vis spectroscopy. Experimental results also confirmed the reduction in band gap energy and recombination rate of charge carriers as compared to pristine α-Bi 2 O 3 sample. PEC study of Se-doped α-Bi 2 O 3 showed an increased photocurrent density, charge carrier density and lowered impedance, which indicates its efficient solar spectrum utilization and better hydrogen generation efficiency. Photocatalytic measurement also revealed higher rate of dye degradation with Se doped α-Bi 2 O 3 . [ABSTRACT FROM AUTHOR]

In this present work, one dimensional (1D) ZnO nanostructures were synthesized by mechanical assisted thermal decomposition process. The samples were characterized by transmission electron microscopy (TEM) for morphology, high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) for structural characterization. Photoluminescence (PL) and Photoluminescence spectra evolution was studied as a function of (i) excitation wavelength (λ Ex: 310–370 nm) and (ii) morphology (nanoneedles and nanorods). PL spectra were observed to be highly asymmetric with strong dependence on excitation wavelength (λ Ex ). PL spectra categorized into two types as a function of excitation wavelength (λ Ex ): I. λ Ex ≤345 nm and II. λ Ex ≥350 nm. The PL spectra were deconvoluted into multiple Gaussian components for each excitation wavelength. The position of each component is a signature of its origin and corresponds to specific visible transition. The transition involving origin from conduction band (CB) are absent for excitation wavelength λ Ex ≥350 nm. The tunable photoresponse is achieved in 1D ZnO nanostructures by varying (i) excitation wavelength and (ii) morphology: nanoneedles to nanorods. PL intensity increases as aspect ratio decrease from nanoneedles to nanorods morphology. This is attributed to non-radiative quenching by near surface defects. [ABSTRACT FROM AUTHOR]

In present study, photocatalytic removal of (i) chromium hexavalent Cr(VI) - heavy metal ion (HMI), (ii) humic acid (HA) - natural organic pollutant and (iii) textile dyes - (cationic: malachite green (MG), methylene blue (MB) and anionic: congo red (CR)) have been carried out using 2D/1D (tungsten disulphide (WS 2) sheets/zinc oxide (ZnO) nanorods) nanocomposite. The synthesized 2D/1D heterostructure acts as a barrier for the recombination of photogenerated species and hence, enhanced the photocatalytic activity. The synthesis of high-purity and crystalline nanocomposite was confirmed by the X-ray diffraction studies. The uniform distribution of ZnO nanorods with an average diameter and length of ∼50 and ∼280 nm, respectively on the surface of WS 2 nanosheets were confirmed by Field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The photocatalytic study shows that the photocatalytic removal efficiencies significantly, enhanced using synthesized nanocomposite from 4.1% to 83.6% for Cr(VI) and 23.5%–75.0% for HA as compared to pristine WS 2 , respectively. The enhanced removal efficiency achieved by the synthesized nanocomposite was explained with the help of (i) higher carrier concentration, (ii) low charge transfer resistance, (iii) appropriate surface charge and (iv) large surface area (85.48 m2/g), as determined from Mott-Schottky (MSK), Electrochemical Impedance Spectroscopy (EIS), Zeta potential, and Brunauer-Emmett-Teller (BET) experiments. The significant improvement in the removal efficiencies were also attributed to the pore size of nanocomposite, pore size belongs to the micropores (0.8–2.0 nm) region which facilitates large active sites for the sorption of contaminants. The observed optical bandgap 2.32 eV of the nanocomposite makes it a favourable material for photocatalytic removal and degradation of contaminants. The semblance of active species in photocatalytic degradation was analyzed through a trapping study and shows that superoxide radicals ( O 2. − ) are the primary species in the removal process. Further, the confirmation of active species was carried out using EPR analysis and value of g-factor is also calculated. The intermediate products during the photocatalytic degradation are analyzed using high performance liquid chromatography (HPLC) technique. The synthesized WZ nanocomposite is an effective and promising material for the treatment of wastewater in the textile, mining, and agricultural industries for getting out the cleaner production. [ABSTRACT FROM AUTHOR]

Printed electronic technologies have sparked interest worldwide because of their capacity to transcend the limitations of existing high-cost electronics based on the fabrication of various devices deploying flexible substrates. Fabricating electrodes on stretchable, bendable, and soft substrates plays a vital role in flexible electronics. Hence this study demonstrates an electrochemical flexible substrate-based aptamer sensor for the Chikungunya virus (CHIKV) antigen over an extensive range of concentrations. In brief, ZnO nanorods were chemically synthesised and characterised by Field emission scanning electron microscopy (FESEM), UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and X-Ray Diffraction (XRD), providing biocompatibility to the aptamer, a biorecognition element. The aptasensor showed a wide linearity (1 ng/ml-10 μg/ml), deploying a voltammetric identification in the presence of 10 mM methylene blue act as a redox-transition substance, with an estimated limit of detection of 1 ng/ml and 25 s as its optimal response time. The applicability of the sensor was further demonstrated by introducing CHIKV-Antigen into commercial serum samples. The built-in sensor has a shelf-life of approximately a month. CHIKV-Antigen can be detected rapidly on a portable platform. As a result, CHIKV can be diagnosed more quickly, allowing for more effective treatment choices. [Display omitted] • In-house, a flexible glove based three electrode system was developed. • Chemically synthesized and thoroughly characterized zinc oxide nanorods were utilized. • The built electrochemical sensor performed in human serum efficiently. • This sensor could be used to diagnose Chikungunya virus antigen. • The application of the Dengue Virus protein confirmed cross-reactivity. [ABSTRACT FROM AUTHOR]

Abstract: A X-ray photoelectron spectroscopy (XPS) depth-profile study of the naturally formed native oxide on polycrystalline Ta sample is probed by observing the core level spectra, valence band spectra and workfunction changes. The present paper addresses the issue of the presence of different Ta suboxides along the depth of the oxide layer. Core level spectra, valence band and workfunction measurements all manifest the transformation of insulating Ta2O5 to metallic Ta with a graded distribution of Ta sub-oxides. Effect of ion-beam irradiation and variation in the synthesis method in determining the profile is discussed. By using different ion-beam energies, it has been shown that the ion-beam induced effects are negligible in the study. Differences in the valence states reported in literature with the present study are attributed to the variations in the growth methods. [Copyright &y& Elsevier]

In the present study, two approaches have been used for enhancing the hydrogenation properties of Pd. In the first approach, metal thin film (Cu, Ag) has been deposited over Pd and hydrogenation properties of bimetal layer Cu (thin film)/Pd(thin film) and Ag(thin film)/Pd(thin film) have been studied. In the second approach, Ag metal nanoparticles have been deposited over Pd and hydrogenation properties of Ag (nanoparticle)/Pd (thin film) have been studied and compared with Ag(thin film)/Pd(thin film) bimetal layer system. The observed hydrogen sensing response is stable and reversible over a number of hydrogen loading and deloading cycles in both bimetallic systems. Alloying between Ag and Pd is suppressed in case of Ag(nanoparticle)/Pd(thin film) bimetallic layer on annealing as compared to Ag (thin film)/Pd(thin film). [ABSTRACT FROM AUTHOR]

Abstract: This study involves monitoring the interface evolution with increasing annealing temperatures in a Cu–Pd bimetal layer structure. The changes due to interdiffusion and ensuing charge transfer are monitored by extensive X-ray photoelectron spectroscopy (XPS) and glancing angle X-ray diffraction (GAXRD) studies. The Pd and Cu core level fingerprinting and change in lattice parameter provide evidence for alloy formation. The changes in the valence band features indicate the formation of new states that are different from the density of states of individual metal surfaces. The study demonstrates the possibility of tuning interface properties by alloy formation that may have specific applications in catalysis, hydrogen sensing and storage. [Copyright &y& Elsevier]

In this study, a novel 2D/2D nanocomposite of MXene and V 2 O 5 was synthesized using a facile hydrothermal approach for the efficient removal of crystal violet (CV), a textile dye from contaminated water to achieve Sustainable Development Goal (SDG) 14; "Save Lives Below Water". Here, the catalytic performance of pristine MXene was prominently boosted with the introduction of ball milled V 2 O 5 as an electron generating agent. The degradation efficiency of synthesized nanocomposite significantly enhanced from 57 % to 92 %, 41 % – 76 % and 7 % – 58 % with an error of ±2 % as compared to pristine MXene at 10, 20 and 30 ppm concentrations of CV, respectively. The effective degradation of pollutants is ascribed to the electron-transfer via S-scheme based mechanism and helps in reducing recombination rate of photogenerated carriers, which could produce hydroxyl radicals (O H.) as a primary species for effectively degradation of pollutants. The superior performance of nanocomposite is attributed to: (i) the optimized surface charge (−27.8 mV), (ii) small value of charge transfer resistance (R ct = 1.3 Ω), (iii) enhanced value of carrier concentration (6.3 X 1032 cm−3), (iv) small recombination rate of excitons and (v) high specific surface area as compared to pristine samples. Moreover, to strengthen the findings, scavenger study and electron paramagnetic resonance (EPR) study were carried out and concluded that hydroxyl radicals (O H.) are the primary species in the mineralization of CV dye. The values of lande g-factor are calculated using EPR plots which comes out to be 2.03 and 2.04 for (O 2. −) and (O H.) radicals, respectively and demonstrates the formation of free radicals during catalytic reactions. The Chemical Oxygen Demand (COD) analysis was carried out before and after the removal of CV using MV nanocomposite and confirms the reduction in COD vlaue of 81.60 %. The reusability experiment confirms stability of synthesized sample and provides a good shred for industrial applications in the treatment of wastewater and getting out cleaner productions and to save marine ecosystem. [Display omitted] • Novel heterostructure of MXene/V 2 O 5 was efficiently synthesized via ball milling and hydrothermal approach. • Heterostructures are highly efficient to fulfil SDG goal 14 and 7, Save Lives Below Water and Water for All. • Removal efficiency enhanced approx. two-fold in case of MV nanocomposite as compared pristine samples. • S-scheme based heterostructures shows highly efficient CV removal performance and reuse convenience. • Enhanced degradation was explained on the basis of Zeta, EIS, Mott-Schottky and EPR analysis. [ABSTRACT FROM AUTHOR]

• Novel photocatalyst MoSe 2 -PPy was prepared and characterized. • Degradation of cationic and anionic dyes in dark and light conditions. • Explanation on the basis of IPCE, TCSPC, BET, zeta potential and EIS measurement. • Intermediates products were studied using LC-MS. • Reusability experiments were also performed. A novel round the clock (day-night) photocatalyst has been developed based on MoSe 2 and polypyrrole (PPy) using two-step method including hydrothermal and in-situ polymerization process. Synthesized samples were characterized by XRD, FESEM, TEM, FTIR, Raman, UV–Visible and XPS techniques. Visible light-induced photocatalytic and adsorption performance were studied by carrying out the degradation of cationic and anionic dyes. The enhancement in degradation performance was attributed to the promoted absorption of photons in the visible region (as evident through IPCE measurement), improved charge separation (as noticed through TCSPC), high surface area (as evident through BET), optimized surface charge (observed by zeta potential), conductive behavior and slow charge transfer resistance (as noticed by EIS). The intermediate products after photocatalytic degradation of dyes were analyzed using LC-MS studies. Our studies showed that MoSe 2 -PPy nanocomposite has the potential efficiency, reusability and stability which make it an ideal catalyst for dye degradation. [ABSTRACT FROM AUTHOR]

This study reports an enhanced and unusual pulse like hydrogen sensing response in Pd nanoparticle layers. The faster H adsorption due to increased surface area and closure of conducting paths as a result of lattice expansion on hydride formation are the primary reasons for this. In comparison, Pd thin films exhibit a slow and subdued sensing response because of the overlap of the above two opposing effects and hydrogen induced lattice strain. Temperature independent conductivity in the temperature range of 20–300 K confirms the presence of interparticle gaps in the case of Pd nanoparticle layers. [ABSTRACT FROM AUTHOR]

In the present work, optimum nanocomposites of MoSe 2 -PANI (polyaniline) were successfully synthesized by modifying the surface of MoSe 2 with PANI to enhance the photocatalytic efficiency. A series of MoSe 2 -PANI nanocomposites with different MoSe 2 to PANI weight percent ratios (1:1, 1:2, 1:3 and 2:1) were prepared by in-situ oxidative polymerization method to study the effect of variation of surface charge on photocatalytic efficiency. Samples were characterized using X-Ray Diffractometer (XRD), Field-Emission Scanning Electron Microscopy (FESEM), Fourier-transform infrared (FTIR) spectroscopy, Diffuse Reflectance spectroscopy (DRS), zeta potential measurements, Photoluminescence (PL) spectroscopy and time-correlated single photon counting (TCSPC). Comparative photocatalytic degradation of cationic dye (Rhodamine B) and anionic dye (Congo red) were performed. The mechanism of degradation was explained using active species trapping experiments. Intermediate products formed during the degradation process were determined using Liquid chromatography-mass spectroscopy (LC-MS). Reaction kinetics for the adsorption of dyes were also studied. MoSe 2 -PANI nanocomposite having MoSe 2 :PANI in 2:1 ratio showed the most significant charge separation and optimized surface charge for photocatalytic degradation of cationic and anionic dye. Image 1 • Synthesis of MoSe 2 :PANI nanocomposite at different weight percent ratio of MoSe 2 to PANI. • Characterization using XRD, FESEM, FTIR, DRS, Zeta potential, TCSPC and PL. • Photocatalytic degradation of cationic (Rhodamine B) and anionic (Congo Red) dye with ultra-high degradation efficiency. • Study of intermediate products using LC-MS. • Study of photocatalysis mechanism with trapping experiment and reaction kinetics. [ABSTRACT FROM AUTHOR]

In this report, MoSe2‐Polyaniline (PANI) nanocomposite with different amounts of MoSe2 (0.05 g, 0.1 g and 0.2 g) were synthesized via in‐situ oxidative polymerization method. The morphology and wt % ratio of nanocomposites was studied using Field emission scanning electron microscopy (FESEM) and Energy dispersive X‐ray spectroscopy (EDX), respectively. Atomic and weight concentration of the nanocomposite was calculated using X‐ray Photoelectron Spectroscopy (XPS) and the results were in agreement with EDX analysis. The optimum nanocomposite as the electrode material for supercapacitor showed the highest specific capacitance of 463 F/g at a scan rate of 5 mV/s and retains ∼72 % specific capacitance after 3000 charge‐discharge cycles. The MoSe2‐PANI nanocomposite attains an energy density of 19.6 Wh/kg at a power density of 12.7 W/kg. The enhancement in the electrochemical activity of the MoSe2‐PANI electrode was achieved by using synergetic effects of electrical double‐layer capacitors (MoSe2 nanosheets) and pseudocapacitors (Polyaniline nanofiber). MoSe2‐PANI nanocomposite showed improved electron and ion transfer mechanism and improvement in the wettability of the electrode material. The thermogravimetric analysis (TGA) confirmed that the nanocomposite has improved thermal stability with mass loss of 28 %. The Brunauer‐Emmett‐Teller (BET) study confirm the high surface area (61.147 m2 g−1) and pore volume (8.595 cm3 g−1) as compared to their pristine samples. The outstanding electrochemical performance has proved that MoSe2‐PANI nanocomposite has a great potential to be an electrode material in energy storage devices. [ABSTRACT FROM AUTHOR]

Dopamine is a major catecholamine neuro-transmitter that plays important function in the human central nervous system's function. Dopamine release disorders are linked to neurological illnesses and depression. To comprehend dopamine's physiological roles, it is vital to monitor dopamine levels at early stage or in regular basis. Many diagnostic procedures are accessible, but they have limitations, thus low-cost and simple ways to test dopamine were needed like colorimetric biosensors. Such biosensors were built with nanoparticles (gold) as a label to help identify targets and the results may be viewed with the naked eye. These gold nanomaterials are available in a range of morphologies, including nanoparticles, nanorods, and others. The present method reported the use of gold nanoparticles (GNPs) and gold nanorods (GNRs) for effective aptamer-based sensing of dopamine. Herein a comparison study was conducted between GNPs and GNRs based apta-sensing of dopamine. Both AuNPs (gold nanoparticles) and AuNRs (gold nanorods) were characterised by SEM (Scanning electron microscope), XRD (X-Ray diffraction) and UV-Vis spectrophotometer (Ultraviolet-Visible spectroscopy). The result claimed that GNRs are more sensitive as they were detecting low concentration of dopamine which was confirmed via UV analysis. Various other parameters such as change in salt concentration, incubation time and interferents were also studied which proved that utilising aptamer and gold-nanorods can be a promising material in the neurotransmitter based diagnosis. [ABSTRACT FROM AUTHOR]

In this work, NaYF4:Eu@TiO2:Er nanomaterial is synthesized via sol–gel method. Various characterization techniques such as FESEM, HRTEM, XRD, EDS FTIR and XPS confirmed the successful formation of NaYF4:Eu@TiO2:Er nanoparticles. The average particle size is found to be 15 nm. Also, UV–Vis–IR and PL spectrometry verified the biluminescent properties of the synthesized material. It is then investigated as biluminescent security ink to be used for anti-counterfeiting applications. The results showed that the designed biluminescent security ink exhibits strong yellow and purple emission under 275 nm and 325 nm excitations, respectively. A written material was kept for 3 months under hot (40 °C) and humid (85%) environment and the obtained results were identical without any deterioration in their luminescence intensities even after such a prolonged time. Moreover, this written material also showed stability under the exposure of different chemical solvents (ethanol, glycerol and acetone). [ABSTRACT FROM AUTHOR]

Treatment options and survival chances are enhanced with early detection of uterine cancer. In this work, an electrochemical paper analytical device (ePAD) for detecting Epidermal growth factor receptor (EGFR), a biomarker for uterine cancer, was demonstrated. The objective of this study is to develop a rapid nano-biosensing method for early detection of fatal uterine cancer. The proposed ePAD is inexpensive, disposable, easy, and repeatable, among other advantageous qualities. The ePAD's Working electrode comprises of silver nanowires. In addition, the use of aptamers has enhanced the performance of the biosensor. The silver nanowires' morphological, optical, elemental content, and phase characteristics were assessed by employing several analytical techniques: transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis spectroscopy. This aptamer-modified ePAD assists in amplifying the signal of the developed platform to identify EGFR. The biosensor utilized the voltametric detection of EGFR in a solution of 0.5 mM potassium ferro/ferri cyanide, which acts as a redox pair by applying a potential of 50 mV/s at the working electrode yielded the highest performance. The designed sensor demonstrated an optimum response broad linearity of 0.01 ng/ml – 1 μg/ml for EGFR, with limit of detection (LOD) of 0.01ng/ml. • The proposed sensor proved good sensitivity and reproducibility. • Silver nanowires that were chemically synthesized and thoroughly characterized were used. • The usage of the PDGF confirmed no cross-reactivity. • The constructed electrochemical sensor worked efficiently in artificial serum and urine sample. • This sensor could be used to detect the wide range of EGFR biomarker for detecting uterine cancer. [ABSTRACT FROM AUTHOR]

• Vertically-aligned carbon nanotubes were synthesized using chemical vapor deposition. • Nanotubes patterns were transferred on flexible substrate by hot compress method. • Carcinoembryonic antigen-related cell adhesion molecule5 was utilized as biomarker. • Fabricated sensor detected colorectal cancer with lower detection limit of 0.92 μM. A genosensor, flexible and low cost as well, has been fabricated to efficiently detect colorectal cancer cell by targeting CEACAM5, a tumor biomarker. Sensing electrode was fabricated with efficient transfer of a pattern of vertically aligned multi-wall carbon nanotubes on flexible polyethylene terephthalate (PET) substrate by hot press technique, a technologically advanced one. The purpose was to make the sensor device stretchable, bendable, transparent, disposable and heat resistant; without losing the pristine character of the electrode material before and after transfer process. Fabricated sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectra (EIS). The sensor response was checked by adding target DNA within a range of 50–250 μM and sensor showed a detection limit of 0.92μM; exhibited good linearity with a regression coefficient of 0.96 obtained through calibration plot. The sensor was found to be highly sensitive, stable and good specificity as binding occurs only with the complementary DNA. Besides, the genosensor showed relative standard deviation of 6.5 % and 6.7 % at respective 100 μM and 150 μM complementary DNA concentrations. Reproducibility and stability are two crucial parameters where the developed sensor have scored extremely well. [ABSTRACT FROM AUTHOR]

There is currently a lot of interest in the construction of point-of-care devices stemming from paper-based origami biosensors. These devices demonstrate how paper's foldability permits the construction of sensitive, selective, user-friendly, intelligent, and maintainable analytical devices for the detection of several ailments. Herein, the first example of the electrochemical aptasensor-based polyvalent dengue viral antigen detection using the origami paper-folding method is presented. Coupling it with an aptamer leads to the development of a new notation known as OBAs, or origami-based aptasensor, that presents a multitude of advantages to the developed platform, such as assisting in safeguarding the sample from air-dust particles, providing confidentiality, and providing a closed chamber to the electrodes. In this paper, gold-decorated nanocomposites of zinc and graphene oxide (Au/ZnO/GO) were synthesized via the chemical method, and characterization was conducted by Scanning Electron Microscope, Transmission Electron Microscope, UV-Vis, and XRD which reveals the successful formation of nanocomposites, mainly helping to enhance the signal and specificity of the sensor by employing aptamers, since isolation and purification procedures are not required. The biosensor that is being demonstrated here is affordable, simple, and efficient. The reported biosensor is an OBA detection of polyvalent antigens of the dengue virus in human serum, presenting a good range from 0.0001 to 0.1 mg/mL with a limit of detection of 0.0001 mg/mL. The reported single-folding ori-aptasensor demonstrates exceptional sensitivity, specificity, and performance in human serum assays, and can also be used for the POC testing of various viral infections in remote areas and underdeveloped countries, as well as being potentially effective during outbreaks. Highlights: (1) First report on origami-based aptasensors for the detection of polyvalent antigens of DENV; (2) In-house construction of low-cost origami-based setup; (3) Gold-decorated zinc/graphene nanocomposite characterization was confirmed via FESEM/UV-Vis/FTIR; (4) Cross-reactivity of dengue-aptamer has been deduced; (5) Electrochemical validation was conducted through CV. [ABSTRACT FROM AUTHOR]

This paper reports an electrochemical paper analytical device (EPAD) for detection of recreational drug; methylenedioxymethamphetamine (MDMA). MDMA is used as an addictive narcotic by youth and there is an urgent need to detect this drug as it is a potential neurotoxic agent. The proposed EPAD represents many advantageous features of being simple, low-cost, consistent and disposable. The working electrode of the EPAD features zinc oxide nanorods (ZnONRs). The morphological, optical, elemental composition and phase analysis of the synthesized ZnONRs has been characterized by field emission scanning electron microscopy (FESEM), UV-Vis spectroscopy, energy dispersive X-ray spectroscopy (EDAX), photo-luminescence (PL) and X-ray diffraction (XRD). The developed sensor showed optimum response at 7.0 pH and wide linear range of 1 µM-1 mM with a low detection limit of 0.1 µM for MDMA. Evaluation of the sensor also revealed best results in terms of analytical recovery (95%) and accuracy (95%). The designed EPAD could prove to be very effective in case of forensic diagnostic applications. This work provides a reliable diagnostic method for remote areas with limited resources, and will also help people who cannot afford expensive medical tests and have limited access to power and trained personnel. [ABSTRACT FROM AUTHOR]

In this article, we report the synthesis, characterization of novel biofriendly 2D/2D heterostructure WS 2 /ZnIn 2 S 4 material in which 2D WS 2 nanosheets are uniformly distributed spatially onto the spherically arranged 2D leaves of ZnIn 2 S 4. We then studied the in-depth photocatalytic degradation activity of this novel nanocomposite and its pristine component materials on cationic dye: malachite green, anionic dye: congo red and reduction of heavy metal: chromium(VI) and the degradation efficiency of composite material was also tested on rhodamine-B, methylene blue, methyl orange dyes and acetaminophen/paracetamol drug. Form factor, structure factor and shape factor analysis has been carried out using X-ray diffractometry (XRD). Bond vibrations, functional groups and phonon vibration mode analysis has been done based on Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Morphological and compositional analysis has been done using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDAX) and X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM). Surface area and pore size/distribution was characterized using Brunauer–Emmett–Teller (BET) method and Barrett-Joyner-Halenda Model. Degradation pathways and intermediate products are proposed using the high-performance liquid chromatography (HPLC). Photocatalytic activity of the nanocomposite WS 2 /ZnIn 2 S 4 is compared with pristine ZnIn 2 S 4 and pristine WS 2 , which shows more than 50% enhancement in both efficiency and rate of degradation/reduction for all the pollutants. A scavenger study was carried out to get insight of primary and secondary reactive oxygen species (ROS) taking part in degradation. Exciton lifetime, surface charge and stability, and flat band positions were studied based on time-correlated single photon counting (TCSPC) also known as time-resolved photoluminescence (TRPL), zeta potential, and Mott-Schottky respectively. Rate kinetics study was performed to analyze the physical and chemical behaviour of the nanocomposite with pollutants in consideration. Results show ∼100%, ∼90%, and ∼95% degradation efficiency by the heterostructure for malachite green (MG), congo red (CR), and reduction of heavy metal chromium (Cr(VI)) respectively within 5 min, which is a huge improvement as compared to pristine WS 2 and pristine ZnIn 2 S 4 , both of which show the efficiencies of only ∼25% to∼75% in all the cases. [Display omitted] • Successful synthesis of novel nanocomposite WS 2 /ZnIn 2 S 4. • More than 90% degradation efficiency within 5 min observed. • Form factor, structure and shape factor analysis performed. • XPS, HPLC, TEM, BET, Mott-Schottky analysis performed. • Both Z-scheme and S-scheme charge transfer observed. [ABSTRACT FROM AUTHOR]

Early identification of ovarian cancer improves treatment options & survival rates. An electrochemical paper analytical device (ePAD) was reported in this study for detecting Platelet-derived growth factor (PDGF), an ovarian cancer biomarker. This research aims to create a quick nano-biosensing approach to recognize deadly ovarian cancer (OC) at an initial phase. The suggested ePAD has numerous positive characteristics, including simple, low-cost, repeatable, & disposable. The ePAD's working electrode contains silver nanoparticles. Furthermore, aptamers have improved the biosensor's functionality. Transmission electron microscopy (TEM), FTIR analysis, X-ray diffraction (XRD), UV–vis spectroscopy, & Zeta potential test were utilized to evaluate the silver nanoparticles' morphological, optical, elemental content, and phase analyses. This aptamer-modified ePAD helps amplify the designed platform's signal to detect PDGF. The interaction of aptamer & PDGF was discovered by lowering the current created by the contact with methylene blue (MB), an anionic indicator. The designed sensor demonstrated an optimum response & broad linearity of 0.01–10.0 μg/ml for PDGF, with 0.01 μg/ml of limit of detection (LOD). [Display omitted] • The developed sensor showed good sensitivity as well as reproducibility. • A chemically synthesized and very well characterized silver-based nanoparticles were utilized. • Cross-reactivity was confirmed by utilizing Urea. • The constructed electrochemical sensor worked efficiently in artificial serum. • This sensor could be used for detecting ovarian cancer biomarker. [ABSTRACT FROM AUTHOR]

• Novel nanocomposite of WS 2 /PPy are synthesized via hydrothermal and in situ oxidative polymerization method for enhancing the catalytic activity of pristine WS 2. • Nanocomposite attained 98.75% and 77.78% removal efficiency for Cr(VI) and HA, respectively. • BET analysis confirms a very high surface area (160.36 m2/gm) of the synthesized nanocomposite. • TCSPC analysis confirms a large average recombination time (7.40 ns) for the photogenerated electron/holes. • Nanocomposites are proved effective and suitable materials for the degradation of contaminants through the photocatalytic approach. In this work, a novel nanocomposite was synthesized by the surface modification of tungsten disulphide (WS 2) with polypyrrole (PPy) for the photocatalytic removal of heavy metal ions (chromium hexavalent (Cr (VI)) and natural organic contaminant (humic acid (HA)). The morphological analysis of synthesized samples was carried out using Field Emission Scanning Electron Microscopy (FESEM) which shows that PPy nanoparticles (NPs) are randomly distributed on the surface of WS 2 nanosheets (NSs). The interlayer spacing of fringe width of WS 2 NSs calculated from High Resolution Transmission Electron Microscopy (HRTEM) studies comes out to be 0.65 nm also in coherence with XRD analysis. Elemental analysis of synthesized nanocomposite was confirmed by using X-Ray Photoelectron Spectroscopy (XPS). The synthesized WP nanocomposite shown enhanced efficiencies (ɳ Cr ∼98.75% and ɳ HA ∼77.78%) as compared to negligible efficiency of pristine WS 2 (∼15% and 16%) and PPy (∼49% and 40%) for the reduction of Cr (VI) and degradation of HA, respectively. The enhanced removal efficiency of nanocomposite was attributed to decrease in the bandgap (2.03 to 1.80 eV), enhanced carrier concentrations (4.0 × 1030 cm−3 to 3.2 × 1031 cm−3) and low recombination rate (1.85 to 7.40 ns) of WP nanocomposite on the incorporation of PPy in WS 2 as evident from UV–Vis, Mott-Schottky technique (MSK) and Time-correlated single-photon counting (TCSPC) decay measurement, respectively. The enhancement in removal efficiency is also attributed to the high surface area (160.36 m2/g) of the nanocomposite as analyzed using Brunauer-Emmett-Teller (BET) technique. The photocatalytic reduction efficiency was also studied as a function of pH (4,7 and 9). The reduction pathways follow second-order rate kinetics with high value of correlation coefficient (R2 ∼ 0.99). The proposed photocatalytic reduction mechanism was supported by a trapping study which shows that the superoxide radicals (⋅ O 2 − ) were the primary species taking part in photocatalytic reaction. Reusability test and stability of materials demonstrates promising photocatalytic performance of the synthesized nanocomposite. Photocatalytic treatment of wastewater using synthesized WS 2 /PPy nanocomposite [Display omitted] [ABSTRACT FROM AUTHOR]

Review: 32 refs. [ABSTRACT FROM AUTHOR]

We present the development of an electrochemical paper-based analytical device (ePAD) for the detection of methamphetamine. Methamphetamine is a stimulant that young people use as an addictive narcotic, and it must be detected quickly since it may be hazardous. The suggested ePAD has the advantages of being simple, affordable, and recyclable. This ePAD was developed by immobilizing a methamphetamine-binding aptamer onto Ag-ZnO nanocomposite electrodes. The Ag-ZnO nanocomposites were synthesized via a chemical method and were further characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-vis spectrometry in terms of their size, shape, and colloidal activity. The developed sensor showed a limit of detection of about 0.1 μg/mL, with an optimum response time of about 25 s, and its extensive linear range was between 0.01 and 6 μg/mL. The application of the sensor was recognized by spiking different beverages with methamphetamine. The developed sensor has a shelf life of about 30 days. This cost-effective and portable platform might prove to be highly successful in forensic diagnostic applications and will benefit those who cannot afford expensive medical tests. [ABSTRACT FROM AUTHOR]

The amount of dopant concentration, alongwith the choice of dopant, is one of the most conducive factor for the favourable outcome for light driven activities of a material. The present paper reports on the synthesis of zinc oxide nanorods doped with different concentrations of copper (Cu-ZnO) by simple, low-cost mechanical assisted thermal decomposition process. The as synthesized samples were tested for visible light driven photo-electrochemical (PEC) and photocatalytic activities on various hazardous dyes using methylene blue (MB), methyl orange and mixed green dye (methyl thymol blue + methylene blue). The study helped us to reveal that highest degradation efficiency was achieved for Cu concentration of 5% in ZnO on MB (91.1% degradation in 40 min). Compared to pure ZnO, the photoactivity of 5% Cu-ZnO composites shows higher photodegradation of dyes. Moreover, the photocatalytic results were found consistent with PEC studies which showed maximum current generation of +9.4 mA for 5% Cu-ZnO (carried out under dark and illumination condition). The mechanism for this enhanced photoactivity has been proposed based on the relationship established between oxygen vacancies and defects generation in the material due to different doping concentrations that directly influence its photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Semiconducting nanocomposites (NCs) has proved their dominance in various energy applications. The facile chemical synthesis of semiconducting hybrid NCs of TiO 2 nanoparticles with SnSe/SnO 2 (SS) nanostructures has been carried out. Structural, morphological, compositions, optical and photo-catalytic (PC) properties of the synthesized materials were then studied by various characterization techniques. The hybrid NC of TiO 2 nanoparticles grown with addition of 0.5 g of SS nanostructures has been observed to exhibit the best PC activity among the other samples. The fitted photoluminescence (PL) spectra of pristine TiO 2 when compared with the other two TiO 2 -SS hybrid NCs showed that the oxygen vacancy (OV) defects play a major role in enhancing the PC property. The samples with superior PC activities have higher intensity of PL emission peak from OVs, efficient charge separation owing to longer lifetime of free charge carriers deduced from time-resolved PL studies and higher surface area. [Display omitted] [ABSTRACT FROM AUTHOR]

Globally, millions of people have been infected with sexually transmitted pathogens, lowering their quality of life in every way, be it emotional, social, or economic. Sexually transmitted diseases (STDs), though, as the very name suggests, are transmitted through sexual contact majorly, but there have been incidences of non-sexual transmissions. Only appropriate diagnosis is the key to managing this condition and stopping it. To identify STDs, several detection methods, such as PCR and serological tests, are available; however, these procedures have numerous drawbacks, such as being less sensitive, costly, and requiring an expert. To overcome such limitations, a newly developing approach known as a biosensor is used to diagnose this disease due to its various advantages, such as early detection, cheap cost, robustness, high sensitivity, and specificity, which make this device more reliable compared to the traditional one. Biosensors for sexually transmitted infections (STIs) have the potential to serve as the backbone required by the World Health Organization's Global health sector plan on STIs from 2016 to 2021. Certain biosensors can also simultaneously detect two or more causative agents via multiplexing, making them much more useful. In recent years, there has been great progress in developing STD biosensors. The presented review aims to outline STDs, their prevalence and severity, the limitations of the current approaches, and how these biosensors are a ray of light in providing efficient, sensitive, and portable devices that are in high demand, as well as their future possibilities. • STD-based biosensor is regarded as an effective and portable diagnostic tool. • The advancement of biosensors in STD diagnosis has been evaluated. • Traditional STD screening methods are also presented, along with their drawbacks. • Comprehensive table summarising biosensors used in STD detection [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles is gaining importance and has been suggested as possible alternatives to chemical and physical methods. The present work reports low-cost, green synthesis of zinc oxide (ZnO) nanoparticles using 25% (w/v) of Azadirachta indica (Neem) leaf extract. The biosynthesized nanoparticles were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). The synthesized ZnO nanoparticles were pure, predominantly spherical in shape with size ranging from 9.6 to 25.5 nm. In the present work, the biosynthesized ZnO nanoparticles have been used for antibacterial and photocatalytic applications. The antibacterial activity of characterized samples was determined using different concentrations of biosynthesized ZnO nanoparticles (20 µg/mL, 40 µg/mL, 60 µg/mL, 80 µg/mL and 100 µg/mL) against Gram-positive and Gram-negative bacteria: Staphylococcus aureus , Streptococcus pyogenes and Escherichia coli using shake flask method. The obtained results revealed that the bacterial growth decreases with increase in concentration of biosynthesized ZnO nanoparticles. In Addition, Gram-positive bacteria seemed to be more sensitive to ZnO nanoparticles than Gram-negative bacteria. The biosynthesized ZnO nanoparticles showed photocatalytic activity under the UV light enhancing the degradation rate of methylene blue (MB), which is one of the main water-pollutant released by textile industries. [ABSTRACT FROM AUTHOR]

Yellow fever virus (YFV) triggers a severe viral hemorrhagic disease with significant clinical and epidemiological significance. The World Health Organization has recognized YFV as a worldwide health emergency. Unfortunately, YFV does not have a specific antiviral treatment. Therefore, an early detection method, which can be easy to perform in a low-resource setting, could increase the chances of survival and the successful management of this disease. Hence, this study developed a paper-based analytical device based on electrochemical sensing to detect the YFV consensus sequence. To the best of our understanding, this study is the first paper-based electrochemical detection platform for YFV detection, employs a screen-printed carbon ink electrode. Printed electrodes on cellulose paper were studied with cyclic voltammetry to demonstrate the electrochemical fundamentals. Cyclic voltammetry (CV) measurements were performed utilizing a potentiostat. The probe DNA (PDNA)-modified electrode was used as a signal modulation platform for hybridization with target DNA (TDNA), which was recognized by a decrease in current produced by the contact of an anionic mediator, Methylene Blue (MB). In addition, an optimum response and a broad linear range of 0.01–100 µM were reported for YFV-TDNA, with a detection limit of 0.01 µM. The suggested approach should be user-friendly for rural locations with low resources and those who cannot afford high-priced medical diagnostics and have limited access to qualified personnel. Because of this, we have decided to deal with this problem by using electrochemical paper-based analytical devices (ePADs) based on electrochemical detection. [Display omitted] • Zinc oxide-based nanoparticles that were chemically synthesized and thoroughly characterized were used. • The usage of the Zika Virus DNA sequence confirmed cross-reactivity. • The constructed electrochemical sensor worked efficiently in artificial serum. • This sensor could be used to detect the DNA sequence of the yellow fever virus. [ABSTRACT FROM AUTHOR]

Broadband photodetection finds indispensable utility across a spectrum of applications, spanning optical communication, spectrum switching, and memory storage. In this work, we demonstrate the fabrication of a heterojunction-based broadband photodetector using visible-infrared activated molybdenum disulfide (MoS 2) and ultraviolet-responsive molybdenum trioxide (MoO 3). The MoO3-x thin films were grown at room temperature using DC sputtering techniques, and subsequent annealing at varied temperatures mitigated defects, increased crystallinity, and produced stoichiometric MoO 3 thin films. Through the sulphurisation of MoO 3 via the chemical vapour deposition (CVD) technique, a heterojunction of transition metal oxide/transition metal dichalcogenide between MoO 3 and MoS 2 is developed. The heterostructure device exhibits broad spectral responsivity, ranging from ultraviolet A to short-wave infrared regions. In particular, ultraviolet ray incidence yields a maximum responsivity of 0.34 A W−1, a minimum noise equivalent power of 1.36 × 10−11 W Hz−1/2, and a maximum quantum efficiency of 119 %. Conversely, under infrared ray illumination, the device achieves a peak responsivity of 13.85 A W−1, a minimum noise equivalent power of 2.89 × 10−13 W Hz−1/2, and the highest quantum efficiency of 1618 %. The ensuing investigations hold promise for advancing heterojunction-based broadband photodetection applications. [Display omitted] • Broad Spectrum: The study addresses the need for broadband photodetectors, covering UVA to SWNIR for diverse applications. • High Responsivity: WO 3 -based photodetector achieves 13.85 A/W at 5V under 1064 nm light with 10 μW power. • MoS 2 /MoO 3 Heterojunction: Introduces a novel MoS 2 /MoO 3 junction, expanding photodetection range. • Sensitive Detector: Reveals a highly sensitive broadband photodetector, ideal for optoelectronics. [ABSTRACT FROM AUTHOR]

Manipulation and targeted navigation of nanobots in complex biological conditions can be achieved by chemical reactions, by applying external forces, and via motile cells. Several studies have applied fuel-based and fuel-free propulsion mechanisms for nanobots movements in environmental sciences and robotics. However, their applications in biomedical sciences are still in the budding phase. Therefore, the current review introduces the fundamentals of different propulsion strategies based on the advantageous features of applied nanomaterials or cellular components. Furthermore, the recent developments reported in various literatures on next-generation nanobots, such as Xenobots with applications of in-vitro and in-vivo drug delivery and imaging were also explored in detail. The challenges and the future prospects are also highlighted with corresponding advantages and limitations of nanobots in biomedical applications. This review concludes that with ever booming research enthusiasm in this field and increasing multidisciplinary cooperation, micro−/nanorobots with intelligence and multifunctions will emerge in the near future, which would have a profound impact on the treatment of diseases. Different types of Advanced Nanodevices on the basis of their morphology and their propulsion mechanisms. (A) Propulsion mechanisms based on Chemical Reactions/Catalysis, (B) Propulsion mechanisms based on external fields, (C) Propulsion mechanisms based on biohybrids. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed an origami-based electrochemical paper-based analytical device (ePAD) for detecting chikungunya virus (CHIKV) antigen. • The study utilized a unique Ag-Au-ZnO ternary nanocomposite for enhanced charge-transfer properties and improved sensor performance. • Achieved a broad linear detection range from 1 ng/ml to 10 µg/ml for CHIKV antigen. • The sensor demonstrated successful detection of CHIKV antigens in serum samples. Electrochemical sensors have drawn significant attention due to their crucial significance in the early detection of infectious illnesses, signifying their critical importance in diagnostic applications. This study's proposed novel aptasensor exhibits a distinctive origami-based ePAD design, utilizing a unique silver-gold and zinc oxide (Ag-Au-ZnO) ternary nanocomposite for enhanced charge-transfer properties. Composite nanomaterials have a lower toxicity level, a higher signal enhancement capacity, increased sensitivity, improved conductivity, superior solubility, enhanced resolution capabilities, and a more straightforward functionalization process than individual nanomaterials. Employing paper, an economically advantageous substrate amenable to large-scale production with an origami-based ePAD is a critical enhancement of the sensor's commendable attributes. Categorized as precision tools with an eco-conscious design, these sensors stand out for their streamlined manufacturing of environmentally sensitive substrates. This research capitalizes on the inherent foldability of paper to construct a three-dimensional multi-angular aptasensor, demonstrating cutting-edge specificity for chikungunya virus (CHIKV) detection. X- ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), UV–vis spectroscopy, and Fourier transmission infrared spectroscopy (FTIR) characterized the nanocomposites. This study also includes aptamers as outstanding and sensitive instruments for quick diagnostic applications. With the use of Cyclic Voltammetry (CV), the analytical response of the aptasensor was carefully evaluated. The study demonstrates a broad linear detection range spanning from 1 ng/ml to 10 µg/ml, with an impressively low limit of detection (LOD) at 1 ng/ml for the CHIKV antigen (CHIKV-Ag), underscoring the novelty and heightened sensitivity of this aptasensor design. Moreover, the aptasensor successfully detects CHIKV antigens in serum samples, and a long stability test demonstrates its practical utility and long-term stability for clinical applications. The proposed study concludes by introducing a novel origami-based paper-based analytical device (ePAD) as a promising tool for the quick, precise, and selective identification of the CHIKV antigen as well as its affordability, easy fabrication, and suitability of POCT testing makes an excellent diagnosing technique in resource-limited settings. [ABSTRACT FROM AUTHOR]