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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]

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]

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]

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]