Highly-sensitive electrochemiluminescence biosensor for detection of inosine monophosphate in meat based on graphdiyne/AuNPs/luminol nanocomposites

Inosine monophosphate(IMP),as a critical umami substance,is one of the most important indicators for evaluating the quality of meat products.Here,a sensitive electrochemiluminescence(ECL)biosensor based on graphdiyne(GDY)/AuNPs/luminol nanocomposites was constructed to detect IMP.The GDY/AuNPs/luminol nanocomposites were synthesized by using simple one-pot method.GDY utilized its 2D framework to disperse and fix gold nanoparticles,which inhibited the agglomeration of gold nanoparticles and greatly improved its stability and catalytic properties.Importantly,GDY/AuNPs/luminol nanocomposites showed excellent catalytic ability and superior ECL activity towards luminol-H_(2)O_(2) systems due to the synergistic effect of GDY and AuNPs.Under optimal conditions,the prepared biosensor exhibited a wide linear range from 0.01 g/L to 20 g/L,a satisfactory limit detection of 0.0013 g/L,as well as an excellent specificity.Moreover,we carried out the precise analysis of IMP in actual meat samples with acceptable results compared to the liquid chromatography.We believe that this work could offer an efficient ECL platform for accurate and reliable report of IMP levels,which is significant for maintaining food quality and safety.

Electrochemical Aptasensor Based on Prussian Blue-Chitosan-Glutaraldehyde for the Sensitive Determination of Tetracycline

In this paper, a novel and sensitive electrochemical aptasensor for detecting tetracycline(TET)with prussian blue(PB) as the label-free signal was fabricated. A PB-chitosan-glutaraldehyde(PB-CS-GA)system acting as the signal indicator was developed to improve the sensitivity of the electrochemical aptasensor.Firstly, the PB-CS-GA was fixed onto the glass carbon electrode surface. Then, colloidal gold nanoparticles(Au NPs) were droped onto the electrode to immobilize the anti-TET aptamer for preparation of the aptasensor.The stepwise assembly process of the aptasensor was characterized by cyclic voltammetry(C-V) and scanning electron microscope(SEM). The target TET captured onto the electrode induced the current response of the electrode due to the non-conducting biomoleculars. Under the optimum operating conditions, the response of differential pulse voltammetry(DPV) was used for detecting the concentration of TET. The proposed aptasensor showed a high sensitivity and a wide linear range of 109-～ 105-M and 105-～ 102-M with the correlation coefficients of 0.994 and 0.992, respectively. The detection limit was 3.2×1010-M(RSD 4.12%). Due to its rapidity, sensitivity and low cost, the proposed aptasensor could be used as a pre-scanning method in TET determination for the analysis of livestock products.

Current Research Situation and Development Countermeasures for Digital Orchards

With the rapid development of modern information technology, digital technology has gradually penetrated into all fields and links of the agricultural industry. Digital orchard reflects the comprehensive application of digital technology in orchard management. This study surveys and analyzes the current development of digital orchard, clarifies the development status and existing problems, and comes up with reasonable recommendations, to provide a certain reference and guidance for the construction of digital orchard in Zibo City of Shandong Province.

Rapid CO_(2)-laser scribing fabrication of an electrochemical sensor for the direct detection of Pb^(2+) and Cd^(2+)

Laser-induced graphene(LIG)is a highly promising preparation material for electrochemical sensors;however,its preparation speed and nanomaterial modification steps significantly limit its mass production.Herein,this study proposed a new laser printing strategy that considerably improved the preparation speed of LIG with excellent electrochemical performance.Using the optimal parameters(laser power of 1%,scribing spacing of 0.12 mm,scribing speed of 100 mm·s^(−1)),it took only 14.2 s to complete the preparation of the detection electrode.Thus,we successfully detected Cd^(2+)and Pb^(2+)without any toxic reagents or electrode modification steps.The limits of detection of the sensor were 0.914 and 0.916μg·L^(−1)for Cd^(2+)and Pb^(2+),respectively,which are significantly lower than the required values for drinking-water quality,according to the World Health Organization guidelines.This study provides a novel approach for the rapid detection of heavy-metal ions.