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Root rot is a highly infectious disease in traditional Chinese medicine (TCM) that spreads quickly and significantly affects the yield and quality of TCM. Therefore, there is an urgent need for accurate and convenient early warning technology to guide root rot control. The root rot of TCM is mainly caused by Fusarium fungi infecting plants. After plants have been infected with fungi, zearalenone (ZEN), fumonisin (FB), fusarium acid (FA), and other compounds will produce duo to Fusarium infects plants to promote metabolism. And the trace expression of these compounds in plants is used as root rot early warning markers (RREWM). Herein, an electrochemical immunosensor was developed for the rapid, convenient, and sensitive detection of zearalenone (ZEN), an early warning marker for Radix isatidis root rot. The immunosensor utilizes Fe3O4@g-C3N4 composite ITO electrode. Initially, the ITO conductive films were modified with Fe3O4@g-C3N4 and gold nanoparticles (AuNPs) through droplet coating and chemical deposition, respectively. Subsequently, the AuNPs were conjugated with zearalenone antibody (ZEN-Ab) to generate high affinity sulfhydryl-bound recognition elements. Under the optimized condition, the sensor demonstrates a linear wide range of 10.00 pg mL−1 to 1.20 × 104 pg mL−1 with a LOD of 3.86 pg mL−1. Additionally, the sensor showed good reproducibility and stability. This study exhibits a convenient, accurate, and low-cost method for detecting early warning markers of root rot in TCM cultivation, which was expected to provide a reliable warning technology for the early warning and prevention of diseases in the planting process of TCM. [ABSTRACT FROM AUTHOR]

A novel electrochemical immunosensor was developed for highly sensitive detection of brain-derived neurotrophic factor (BDNF), a well-known depression marker. The immunosensor was fabricated by modifying indium tin oxide-coated polyethylene terephthalate (ITO-PET) with N-doped graphene-polyaniline (NG-PANI) and gold nanoparticles (AuNPs) to enhance the conductivity and protein loading capacity. Subsequently, BDNF was immobilized onto the electrode surface via gold-sulfur bonds, followed by the attachment of biotinylated antibody (Biotin-Ab) and horseradish peroxidase-avidin (HRP-Avidin) to create the final immunosensor (HRP-Avidin–Biotin-Ab-BDNF-AuNPs/NG-PANI/ITO-PET). The proposed immunosensor exhibited a linear range of determination (0.781–400 pg/mL) with a low limit of detection (LOD) of 0.261 pg/mL (S/N = 3) and excellent reproducibility (RSD = 1.4%) and stability (92.7%, RSD = 3.1%). Additionally, the immunosensor demonstrated good anti-interference performance and good recovery (98.1–107%). To evaluate the practical utility of the immunosensor, BDNF levels were quantified in the serum of mice with depression induced by chronic unpredictable mild stress (CUMS). The results indicated that the serum BDNF levels were significantly decreased in the depression model group compared with the control group, highlighting the potential of this immunosensor for clinical detection of BDNF in depression diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Schematic representation of constructing CS-Fc@SPCE electrochemical immunosensor for the detection of cTnI. [Display omitted] • A label-free electrochemical immunosensor based on ferrocene derivatives amplified signal for cTnI detection was created. • A novel redox-active hybrid material, CS-Fc, which significantly increases the electron transfer rate. • The immunosensor showed excellent analytical performances in the assay of AMI warning biomarker – cTnI. As a biomarker of acute myocardial infarction (AMI), screening for cardiac troponin I (cTnI) has extremely high clinical sensitivity and specificity, and is extremely important for early intervention and risk assessment of AMI. Therefore, a novel redox-active hybrid material, CS-Fc, was synthesized by the Schiff base reaction of chitosan (CS) and ferrocene-carboxylic acid (Fc(COOH)) to form an amide group bonded together, which was used as a substrate-modified material for screen-printed carbon electrode (SPCE), and then assembled with an antibody (Ab), which was constructed into a label-free electrochemical immunosensor for the highly sensitive and rapid detection of cTnI in this study. The redox activity and biocompatibility of the highly stable and conductive composite CS-Fc significantly increased the effective specific surface area, electron transfer rate, and achieved effective amplification and specific analysis of the response signal. Under the optimized experimental conditions, the immunosensor showed a good linear relationship between its response signal and cTnI concentration in the range of 2.44 × 10−2 ∼ 2.50 × 101 ng mL−1, with a limit of detection (LOD) as low as 3.70 × 10−3 ng mL−1 (3σ, n = 11). Meanwhile, when used for the detection of cTnI in actual serum samples, it showed better reproducibility and stability, and the analytical results were better than those of the ELISA method, which indicated that it has a great potential for the accurate and rapid detection of cTnI in serum samples. In addition, it also provides a reliable means and scientific basis for process screening, early warning and prognostic risk assessment of AMI. [ABSTRACT FROM AUTHOR]

Abstract The porous graphene functionalized black phosphorus composite (PG-BP) was successfully synthesized via strong coherent coupling between porous graphene surface plasmons and anisotropic black phosphorus localized surface plasmons by the method of penetration of infrared ray using infrared drying. And it was used to fabricate a novel high-sensitive electrochemical sensor for determination of bisphenol A (BPA) in daily use and biological samples. The PG-BP had been characterized by infrared spectroscopy, Raman, X-ray photoelectron spectroscopic, scanning electron microscopy and energy dispersive spectrometer, indicating that PG-BP with the large specific surface area and good electrical conductivity was successfully prepared. In addition, electrochemical properties of the modified materials are comparably explored by means of impedance spectroscopy and cyclic voltammograms. Under the optimal conditions, BPA was determined quantitatively using differential pulse voltammetry. The results showed that the BPA detection current has a good linear relationship in the range of 4.3 × 10−8–5.5 × 10−5 mol/L with a detection limit of 7.8 × 10−9 mol/L (S/N = 3). Results from the present work illustrate the prominent performance of PG-BP as a sensing channel for BPA sensor application and the huge potential of PG-BP as an electrode material. Graphical abstract Schematic representation of PG-BP/GCE fabrication and electrochemical detection of BPA. Unlabelled Image Highlights • The PG-BP were successfully prepared based on the strong coupling between porous graphene and black phosphorus. • This is the first research on the electrochemical sensors based on PG -BP composite. • The proposed electrochemical sensor exhibited a broad detection range and low detection limit for BPA. • The electrochemical sensor can be used for the sensitive and efficient analysis of BPA in real samples. [ABSTRACT FROM AUTHOR]

In this study, a novel electrochemical immunosensor for early screening of depression markers-heat shock protein 70 (HSP70) was successfully developed based on the porous graphene (PG) with huge specific surface area and excellent structure. Benefiting from the strong adsorption and good bioactivity of PG which was initially prepared via a simple pyrolysis process, a variety of heat shock protein70 (HSP70) can be firmly loaded on the PG to construct the basic electrode (HSP70/PG/GCE)，which was characterized by the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the HSP70 fixed on the surface of basic electrode and the HSP70 in the samples can competitively combine with the horseradish peroxidase labeled human HSP 70 antibody (HRP-Strept-Biotin-Ab). As a result, it presented a negative correlation between the concentration of HSP70 in samples and the detection signal of the proposed electrochemical immunosensor (HRP-Strept-Biotin-Ab-HSP70/PG/GCE) in the test liquid. The application of PG with excellent electrical conductivity in construction of immunosensor remarkably improved the sensitivity of the immunosensor for detection of HSP70. The proposed immunosensor demonstrated a wide linear range of 0.0448 ~ 100 ng/mL with a low detection limit of 0.02 ng/mL at 3σ. Moreover, the proposed immunosensor could be applied for the sensitive and efficient detection of HSP70 in real samples with good precision, acceptable stability, reproducibility and satisfactory results. Therefore, the HSP70 immunosensor provides a novel and convenient method for early clinical screening of depression markers-heat shock protein 70. [ABSTRACT FROM AUTHOR]

In this study, polyaniline functionalized graphene quantum dots composite with excellent performance was successfully prepared by situ polymerized, and it was applied to fabricate electrochemical sensor for analysis of calycosin in the complex samples of traditional Chinese medicine. The polyaniline functionalized graphene quantum dots composite was characterized by Fourier transform infrared spectroscopy and Raman analysis, to indicate that polyaniline functionalized graphene quantum dots composite was successfully synthesized. The morphology and microstructure of the modified electrodes were characterized by Scanning electron microscope and Transmission electron microscope. According to the results of cyclic voltammetry and electrochemical impedance spectroscope, the glassy carbon electrode modified with polyaniline functionalized graphene quantum dots composite significantly increased the electron transfer rate on the surface of sensor. Under the optimized conditions, the fabricated sensor was used for the analysis of calycosin in Radix Hedysari and Radix Astragali by differential pulse voltammetry, which displayed acceptable reproducibility, long-term stability, good selectivity and sensitivity. The proposed sensor exhibited a wide detection range (1.1 × 10 −5 –3.52 × 10 −4  mol/L) with a detection limit of 9.8 × 10 −6  mol/L (S/N = 3). This study provided a novel and convenient method for rapid evaluation of the quality of Radix Hedysari and Radix Astragali . [ABSTRACT FROM AUTHOR]

Schematic representation of constructing ds-DNA/AuNPs/AC@CS/GCE electrochemical biosensor for evaluating the antioxidant activity of SMEF from HP L. [Display omitted] • A stable and convenient electrochemical biosensor for evaluating the antioxidant activity of SMEF from HP L. is fabricated. • The prepared AuNPs/AC@CS with a large specific surface area excellent electrical conductivity and structure can amplify the signal of the biosensor. • This study would provide an effective method for assessment of fermentation products of endophytic fungi from medicinal plants. Due to the variety and activity of secondary metabolites of endophytic fungi (SMEF) from medicinal plants, and the operation cumbersome of existing methods for evaluating the activity, there is urgent to establish a simple, efficient and sensitive evaluation and screening technology. In this study, the prepared chitosan functionalized activated carbon (AC@CS) composite as the electrode substrate material was used to modify glassy carbon electrode (GCE), and the gold nanoparticles (AuNPs) was deposited on AC@CS/GCE by cyclic voltammetry (CV). A ds-DNA/AuNPs/AC@CS/GCE electrochemical biosensor for evaluating the antioxidant activity of SMEF from Hypericum perforatum L. (HP L.) was fabricated using the method of layer by layer assembly. The experimental conditions affecting the evaluation results of the biosensor were optimized by square wave voltammetry (SWV) using Ru(NH 3) 6 3+ as the probe, and the antioxidant activity of various SMEF from HP L. was evaluated by the proposed biosensor. Meanwhile, the results of the biosensor were also verified by UV–vis. According to the optimized experimental results, the biosensors had a high levels of oxidative DNA damage at pH 6.0 and Fenton solution system with Fe2+ to OH− ratio of 1:3 for 30 min. Among the crude extracts of SMEF from roots, stems and leaves of HP L., the crude extracts from stems presents a high antioxidant activity, but it was weaker than l -ascorbic acid. This result was consistent with the evaluation results of UV–vis spectrophotometric method, also the fabricated biosensor presents high stability and sensitivity. This study not only provides a novel, convenient and efficient way for rapid evaluating the antioxidant activity of a wide variety of SMEF from HP L., but also provides a novel evaluation strategy for the SMEF from medicinal plants. [ABSTRACT FROM AUTHOR]

A novel lobetyolin electrochemical sensor based on a magnetic functionalized reduced graphene oxide/Nafion nanohybrid film has been introduced in this work. The magnetic functionalized reduced graphene oxide was characterized by fourier transform infrared spectroscopy, atomic force microscope, X-ray diffraction, transmission electron microscopy and thermogravimetric analysis. The scanning electron microscopy characterized the morphology and microstructure of the prepared sensors, and the electrochemical effective surface areas of the prepared sensors were also calculated by chronocoulometry method. The electrochemical behavior of lobetyolin on the magnetic functionalized reduced graphene oxide/Nafion nanohybrid modified glassy carbon electrode was investigated by cyclic voltammetry and differential pulse voltammetry in a phosphate buffer solution of pH 6.0. The electron-transfer coefficient (α), electron transfer number (n), and electrode reaction rate constant (Κs) were calculated as 0.78, 0.73, and 4.63 s − 1 , respectively. Under the optimized conditions, the sensor based on magnetic functionalized reduced graphene oxide/Nafion showed a linear voltammetric response to the lobetyolin concentration at 1.0 × 10 − 7 to 1.0 × 10 − 4 mol/L with detection limit (S/N = 3)of 4.3 × 10 − 8 mol/L. The proposed sensor also displayed acceptable reproducibility, long-term stability, and high selectivity, and performs well for analysis of lobetyolin in real samples. The voltammetric sensor was successfully applied to detect lobetyolin in Codonopsis pilosula with recovery values in the range of 96.12% –102.66%. [ABSTRACT FROM AUTHOR]

A sensitively competitive electrochemical immunosensor for the detection of cortisol was successfully developed based on gold nanoparticles and magnetic functionalized reduced graphene oxide (AuNPs/MrGO). In order to construct the base of the immunosensor, the MrGO was initially fabricated by chemical cross-linking and used to modify the nafion pretreated glassy carbon electrode. Subsequently, the surface of electrode was modified by AuNPs via electrochemical deposition. A variety of cortisol (Cor) can be firmly loaded in the AuNPs/MrGO with large specific surface area and good bioactivity to construct the basic electrode (Cor/AuNPs/MrGO/Nafion@GCE), which was characterized by the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the cortisol on the surface of basic electrode and samples can competitively combine with the cortisol antibody labelled by horseradish peroxidase (HRP-Strept-Biotin-Ab). Finally, the detection signal of electrochemical immunosensor (HRP-Strept-Biotin-Ab-Cor/AuNPs/MrGO/Nafion@GCE) in the test liquid had negative correlations with the concentration of cortisol in samples. The AuNPs/MrGO with excellent electrical conductivity being applied, the electrochemical response of the immunosensor was immensely amplified. The immunosensor displayed excellent analytical performance for the detection of cortisol range from 0.1 to 1000 ng/mL with a detection limit of 0.05 ng/mL at 3σ. Moreover, compared the developed immunoassay with commercially available enzyme linked immunosorbent assay, the proposed method showed good precision, acceptable stability and reproducibility, indicating the immunosensor could be used for the sensitive, efficient and real-time detection of cortisol in real samples. Therefore, the present strategy provides a novel and convenient method for clinical determination of cortisol. [ABSTRACT FROM AUTHOR]

Sleep debt (SD) is one of the important triggers for causing not only physiological and mental illness but also dangerous work. Therefore, achieving an early and objective assessment of SD is of great significance in the precaution against SD-related diseases and unsafe work. Here, an ultrasensitive electrochemical immunosensor was constructed for analysis of SD biomarker amyloid-β (A β). The gold nanoparticles/chitosan-coated polyaniline-functionalized activated carbon (AuNPs/AC@PANI@CS) composites were employed as the sensing platforms. Since PANI and AC can form an effective conductive path, it can effectively enhance the penetration of electrolytes on the electrode surface and the rapid transport of charges and ions, significantly enhancing the electrochemical response signal of the immunosensor. Under the optimized experimental conditions, the fabricated immunosensor had a wide linear range of 1.95 pg mL−1 to 1000.00 pg mL−1, with a low detection limit of 0.014 pg mL−1. This study not only provides an effective method for the accurate and rapid detection of A β , but also offers a novel evaluation strategy for the objective assessment of SD and the study of related pathological mechanisms. AuNPs/AC@PANI@CS signal amplified electrochemical immunosensor for sensitive detection of amyloid-β (Aβ). [Display omitted] • A highly sensitive and selective electrochemical immunosensor for the determination of amyloid-β (A β) was fabricated. • The prepared AC@PANI with a large specific surface area, excellent electrical conductivity and structure can amplify the signal of the immunosensor. • The proposed immunosensor can be used to sensitively and efficiently analyze A β in serum samples. • This method would provide an effective method for the objective assessment of sleep debt. [ABSTRACT FROM AUTHOR]

A sensitive electrochemical sensor based on bovine serum albumin (BSA)/poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene nanosheets (PDDA-G) composite film modified glassy carbon electrode (BSA/PDDA-G/GCE) had been developed to investigate the oxidative protein damage and protections of protein from damage by flavonoids. The performance of this sensor was remarkably improved due to excellent electrical conductivity, strong adsorptive ability, and large effective surface area of PDDA-G. The BSA/PDDA-G/GCE displayed the greatest degree of BSA oxidation damage at 40 min incubation time and in the pH 5.0 Fenton reagent system (12.5 mM FeSO 4 , 50 mM H 2 O 2 ). The antioxidant activities of four flavonoids had been compared by fabricated sensor based on the relative peak current ratio of SWV, because flavonoids prevented BSA damage caused by Fenton reagent and affected the BSA signal in a solution containing Co(bpy) 3 3 + . The sensor was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). UV–vis spectrophotometry and FTIR were also used to investigate the generation of hydroxyl radical and BSA damage, respectively. On the basis of results from electrochemical methods, the order of the antioxidant activities of flavonoids is as follows: (+)-catechin > kaempferol > apigenin > naringenin. A novel, direct SWV analytical method for detection of BSA damage and assessment of the antioxidant activities of four flavonoids was developed and this electrochemical method provided a simple, inexpensive and rapid detection of BSA damage and evaluation of the antioxidant activities of samples. [ABSTRACT FROM AUTHOR]

Developing wearable flexible biosensors with excellent electrical conductivity and outstanding flexibility simultaneously for disease diagnosis and health monitoring is a current hot topic in the field of sensor research. In this study, nitrogen-doped graphene (N-Gr) and gold nanoparticles (AuNPs) were successively deposited onto ITO-PET flexible conductive films by chemical deposition, and then a flexible electrochemical immunosensor with high sensitivity and selectivity was constructed for detecting depression markers by exploiting the high affinity between AuNPs and the sulfhydryl groups of depression marker (DM) antibody. Due to the composite of N-Gr, AuNPs and ITO-PET, the prepared flexible sensor can maintain a relatively stable electrical signal response regardless of the deformation such as spiral, rolling, and bending, without shedding or fracture of the N-Gr and AuNPs, and can also significantly amplify the electrochemical response signal of the immunosensor. Under optimized experimental conditions, the fabricated immunosensor showed good linearity over a wide range of 0.023–300.00 ng/mL with a low detection limit of 0.010 ng/mL (3σ, n = 5), when it was used for the determination of depression markers-human Apo-A4 in 100% whole serum samples. The flexibility of the constructed immunosensor and the stability and sensitivity of biomolecular analysis are expected to be further made into implantable depression marker in-situ monitoring probe with the help of micro-machining technology, which will develop a promising method for objective, efficient and accurate clinical diagnosis of depression. Schematic representation of constructing AuNPs@N-Gr@ITO-PET-based electrochemical immunosensor for determination of apolipoprotein A4 (Apo-A4). [Display omitted] • A highly sensitive and selective flexible immunosensor for determination of human apolipoprotein A4 (Apo-A4) has been fabricated. • The prepared AuNPs@N-Gr with large specific surface area, excellent electrical conductivity and outstanding flexibility can amplify the signal of immunosensor. • The proposed immunosensor can be used to sensitively and efficiently analyze apolipoprotein A4 (Apo-A4) in serum samples. • This method would provide a promising potential in early clinical screening and diagnosis of depression. [ABSTRACT FROM AUTHOR]

• ZIF-8@N-Gr with excellent performance was prepared. • ZIF-8@N-Gr can be used in immunosensor development for Apo-A4 detection. • Lower limit of detection and wider linear range than ELISA kit. • Determination of Apo-A4 in plasma with no need for sample treatment. The fabrication of electrochemical biosensors to directly, rapidly and ultrasensitively detect disease markers in urine or blood samples has become a new and competitive challenge in the field of sensor research. In this paper, a novel electrochemical immunosensor with high selectivity and sensitivity for the detection of the depression marker human apolipoprotein A4 (Apo-A4) was successfully constructed using zeolite imidazole ester metal organic skeleton-nitrogen doped graphene composites (ZIF-8@N-Gr). To this end, because of the higher surface area and biocompatibility, ZIF-8 with abundant biomolecular binding sites provided a good microenvironment for effectively immobilizing antigens. ZIF-8@N-Gr presented a flake structure, as the electrode displayed excellent electrical conductivity, which enhanced the electron transfer and significantly amplified the current signal of the immunosensor. More importantly, these immunosensors are capable of assaying human apolipoprotein A4 (Apo-A4) in 100% serum without suffering from any significant biological interference. Under optimized experimental conditions, the sensor was used for the analysis of whole serum samples and presented a wide linear range from 1.47 × 10−10 g/mL to 3.00 × 10−7 g/mL with a low detection limit of 8.33 × 10−11 g/mL (3σ, n = 15). The satisfactory results of human serum sample analysis indicated that the proposed immunosensor had promising potential in the clinical diagnosis of depression. [ABSTRACT FROM AUTHOR]

The accurate and sensitive analysis of rheumatoid arthritis(RA) trace biomarkers is essential for early warning and diagnosis of RA, while anti‐cyclic citrullinated peptide antibody (anti‐CCP‐ab) is a specific one. In this study, a simple label‐free electrochemical immunosensor for the detection of anti‐CCP‐ab was constructed with nitrogen‐doped graphene (N−G) and gold nanoparticles (AuNPs). The proposed non‐enzyme immunosensor had exhibited high specificity, selectivity, and stability in the linear calibration curve range from 0.125∼2000 pg mL‐1 and has been successfully used in the detection of anti‐CCP‐ab in human serum, providing a new idea for the early diagnosis of RA. [ABSTRACT FROM AUTHOR]

As a new type of conductive material, polyaniline functionalized graphene quantum dots (PAGD), which were prepared by in-situ polymerization had been used to construct a novel electrochemical immunosensor for early screening of depression markers-heat shock protein 70 (HSP70). Profiting from the huge specific surface area, good bioactivity and excellent structure of PAGD, a variety of heat shock protein 70 (HSP70) was firmly loaded on the surface of PAGD for successful construction of basic electrode (HSP70/PAGD/GCE), which was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the HSP70 fixed on the surface of basic electrode and the HSP70 in the samples can competitively combine with the horseradish peroxidase labeled human HSP70 antibody (HRP-Strept-Biotin-Ab). As a result, there is negative correlation between the concentration of HSP70 in samples and the detection signal of the proposed electrochemical immunosensor (HRP-Strept-Biotin-Ab-HSP70/PAGD/GCE) in the test liquid. Under conditions optimized for determining HSP70, wide linearity was obtained in the range of 0.0976–100 ng/mL, with a low detection limit of 0.05 ng/mL at 3σ. Moreover, the proposed electrochemical immunosensors was successfully applied to detect HSP70 in plasma samples, and exhibited good precision, acceptable stability and reproducibility. Therefore, this study provides a novel and convenient method for early clinical screening of depression markers, and also provides a reliable and objective analysis method for the diagnosis of depression at the molecular level. Unlabelled Image • The polyaniline functionalized graphene quantum dots (PAGD) was successfully prepared. • The HRP-Strept-Biotin-Ab-HSP70/PAGD/GCE immunosensor for determination of HSP70 was successfully fabricated. • The proposed immunosensor exhibited a broad detection range and low detection limit for HSP70. • It provides a novel and convenient method for early clinical screening of depression markers-HSP70 in real samples. [ABSTRACT FROM AUTHOR]

Leptin is a vital biomarker of non-alcoholic fatty liver (NAFLD), and its evaluation of the concentration level in vivo is of great significance to NAFLD diagnosis. Therefore, it is pressing to develop a method for rapid and sensitive detection of leptin. This paper describes an environmentally friendly and label-free immunosensor based on porous graphene functionalized black phosphorus (PG-BP) composite to detect of leptin. The PG-BP was synthesized via strong coherent coupling between porous graphene (PG) surface plasmons and anisotropic black phosphorus (BP) localized surface plasmons, which made the electrochemical performance of PG and BP synergistic as well as increased the stability and conductive capability of BP material. The PG-BP modified electrodes was further prepared by gold nanoparticles, cysteamine, and glutaraldehyde in turn. Due to the cross-linking effect of glutaraldehyde, anti-leptin can be firmly fixed. These properties of the platform improved the conductive capability of the immunosensor and enhanced the load capacity of the proteins, thereby, the sensitivity of the immunosensor was significantly increased. Under the optimal conditions, the proposed immunosensor exhibited a wide linear range of 0.150–2500 pg/mL with a low detection limit of 0.036 pg/mL. The leptin immunosensor displayed excellent selectivity and anti-interference ability, which could be used for early screening and diagnosis of clinical NALFD. • A BSA/anti-leptin/Glu/Cys/AuNPs/PG-BP/GCE immunosensor was successfully fabricated. • The proposed immunosensor was successfully used for the detection of leptin with a wide range of detection and low detection limits. • The immunosensor can be used for the sensitive, efficient and real-time analysis of leptin in real samples. • The immunosensor is expected to provide a reliable, real-time and convenient method for clinical trials of NAFLD markers. [ABSTRACT FROM AUTHOR]

A pectic polysaccharide (named as CPP1c) extracted from Codonopsis pilosula was evaluated for its structural features and potential of immune-modulating activities in an aging mouse model of senescence accelerated mouse prone 8 (SAMP8) in vitro and in vivo . The relative molecular weight and the absolute molecular weight of CPP1c were 1.26 × 10 5 Da and 1.49 × 10 5 Da, respectively. Investigation of structural features by a combination of chemical and instrumental analysis showed CPP1c was composed of →1)-α- l - R ha p -(2,4→, →1)-α- l -Ara f -(5→, →1)-α- d -Gal p -(6→ and →1)-α- d -Gal p A-(4→ in a molar ratio of 3:1:2:33. CPP1c could promote lymphocyte proliferation, modulate the percentage of CD4 + , CD8 + , CD28 + and CD152 + T cells and enhance the production of IL-2, TNF-α and IFN-γ. Moreover, PCR assay revealed CPP1c augmented the expressions of CD28, PI3 K and p38MAPK mRNA, and the increase of protein expressions of the same genes was also confirmed by western blot analyses. In addition, CPP1c had the potential of promoting the homing of lymphocytes. Taking all factors into consideration, we deduced CPP1c might exert its immunostimulating potency via promoting T cell activation by TCR/CD28 signaling pathways. [ABSTRACT FROM AUTHOR]

Four novel Salan Hf(IV) complexes stabilized by 2,6-dipicolinic acid (Dipic) were synthesized and characterized by 1H, 13C NMR and X-ray diffraction spectroscopy. These Hf(IV) bis -chelates could be obtained in good to excellent yields (88%–91%) and demonstrated rather good stability in aqueous media and on silica gel. [L 2 Hf (IV) Dipic 4-H,Cl ] containing steric bulk L 2 were stable in about 10% H 2 O (H 2 O/THF (v/v)), however, [L 1 Hf (IV) Dipic 4-H,Cl ] with non-steric L 1 could slowly dissociate and release nontoxic L 1. [L 1 – 2 Hf (IV) Dipic 4-Cl ] showed excellent anti-tumoral activity in the range of cisplatin (Hela S3: IC 50 = 3.5 ± 0.4 μM, Hep G2: IC 50 = 11.2 ± 2.1 μM). In addition, the cellular uptake and apoptosis investigation of [L 1 Hf (IV) Dipic 4-Cl ] suggested a fast cellular uptake process against Hela S3 cells with an almost exclusive induced apoptosis cell death path. Novel [SalanHf (IV) Dipic] demonstrate potent anti-tumoral activity and stability with rapid cellular uptake and exclusive induced Hela S3 cell apoptotic death. [Display omitted] • Salan Hf(IV) bis -chelated complexes demonstrated excellent anti-tumoral activity in the range of cisplatin. • Salan Hf(IV) bis -chelated complexes exhibit a fast cellular uptake and an almost exclusive induced Hela S3 cell apoptosis. • The Hf(IV) complexes bearing steric demanding Salan exhibit both good stability and anti-tumoral activity. • Salan Hf(IV) bis -chelated complexes demonstrate good selectivity to tumor cells. [ABSTRACT FROM AUTHOR]