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Background: Emtricitabine (FTC) is a commonly prescribed anti-human immunodeficiency virus (HIV) drug that has been classified as an emerging environmental pharmaceutical micropollutant due to its poor metabolism, refractory nature to wastewater treatment, continuous discharge with wastewater effluent and accumulation in the aquatic environment. Although there are no reported limits and toxicity of the drug in the environment yet, it is crucial to develop onsite, rapid, selective and ultrasensitive water sensing systems for FTC to ensure efficient risk management and environmental sustainability., Results: Herein, a molecularly imprinted poly(para-aminobenzoic acid) (MIP) was electrochemically prepared on iron oxide nanoparticles modified glassy carbon electrode (MIP/Fe 3 O 4 NPs/GCE) for selective detection of FTC using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). During the detection, the voltammetric signal of the MIP sensor decreased with increasing concentrations of the non-electroactive FTC, indicating hindrance of the MIP sensor's redox activity by the binding analyte. The sensor generated a calibration curve with a linear dynamic range of 1.24-24.7 μg L -1 and a limit of detection (LOD) and limit of quantification (LOQ) of 0.439 and 1.30 μg L -1 , respectively. Moreover, the MIP sensor was 5.2 times more sensitive than the control sensor, a non-imprinted polymer (NIP) sensor, and had a higher apparent binding affinity for FTC than the NIP sensor. The MIP/PABA-Fe 3 O 4 /GCE-based sensor achieved recoveries of 98.8 %-101.5 % for applications in real wastewater and drinking water samples., Significance: The combination of Fe 3 O 4 nanoparticles, electrically conducting polymer, and the MIP technology produced a novel, simple, cost-effective, and high-performance voltammetric MIP sensor for an anti-HIV drug, FTC. The result of this study shows that the sensor holds a significant promise for future onsite monitoring of emtricitabine in wastewater, pharmaceutical, and biological samples without prior sample pretreatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tuberculosis (TB) is a worldwide burden whose total control and eradication remains a challenge due to factors including false positive/negative diagnoses associated with the poor sensitivity of the current diagnostics in immune-compromised and post-vaccinated individuals. As these factors complicate both diagnosis and treatment, the early diagnosis of TB is of pivotal importance towards reaching the universal vision of a TB-free world. Here, an aptasensor for signaling an interferon gamma (IFN-γ) TB biomarker at low levels is reported. The aptasensor was assembled through gold-thiol interactions between poly(3,4-propylenedioxythiophene), gold nanoparticles, and a thiol-modified DNA aptamer specific to IFN-γ. The aptasensor sensitively detected IFN-γ in spiked pleural fluid samples with a detection limit of 0.09 pg/mL within a linear range from 0.2 pg/mL to 1.2 pg/mL. The good performance of the reported aptasensor indicates that it holds the potential for application in the early diagnosis of, in addition to TB, various diseases associated with IFN-γ release in clinical samples.

This study is a first-time report of the development of a mercaptosuccinic acid-nickel selenide quantum dots (MSA-NiSe 2 QDs)-based electrochemical aptasensor for brain natriuretic peptide (BNP) detection. Herein, novel MSA-NiSe 2 QDs were synthesized by microwave irradiation. Microscopic and structural analysis revealed that the QDs are spherical with an average diameter of 2 nm. In the presence of the as-prepared QDs, an amine-modified DNA aptamer sequence was attached to a disposable sensing interface through 1-ethyl-3-(3-dimenthylaminopropyl) carbodiimide/ N -hydroxysuccinimide coupling chemistries. Electroanalytical analysis revealed that the developed QDs-based electrochemical aptasensor is highly selective towards BNP and successfully detected BNP in both physiological buffer and human plasma samples with detection limits of 5.45 pg mL -1 and 31.95 pg mL -1 , respectively. Moreover, the results revealed a 3-fold enhancement in the loading capacity of the BNP aptamer in the presence of MSA-NiSe 2 QDs. By taking advantage of the physical and electronic properties of the novel QDs these materials can be easily adapted to other diagnostic approaches.

We report the preparation of poly (propylene imine) dendrimer (PPI) and CdTe/CdSe/ZnSe quantum dots (QDs) as a suitable platform for the development of an enzyme-based electrochemical cholesterol biosensor with enhanced analytical performance. The mercaptopropionic acid (MPA)-capped CdTe/CdSe/ZnSe QDs was synthesized in an aqueous phase and characterized using photoluminescence (PL) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray power diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy. The absorption and emission maxima of the QDs red shifted as the reaction time and shell growth increased, indicating the formation of CdTe/CdSe/ZnSe QDs. PPI was electrodeposited on a glassy carbon electrode followed by the deposition (by deep coating) attachment of the QDs onto the PPI dendrimer modified electrode using 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) as a coupling agent. The biosensor was prepared by incubating the PPI/QDs modified electrode into a solution of cholesterol oxidase (ChOx) for 6 h. The modified electrodes were characterized by voltammetry and impedance spectroscopy. Since efficient electron transfer process between the enzyme cholesterol oxidase (ChOx) and the PPI/QDs-modified electrode was achieved, the cholesterol biosensor (GCE/PPI/QDs/ChOx) was able to detect cholesterol in the range 0.1⁻10 mM with a detection limit (LOD) of 0.075 mM and sensitivity of 111.16 μA mM -1 cm -2 . The biosensor was stable for over a month and had greater selectivity towards the cholesterol molecule.