•Th-mpg-C3N4 was synthesized for the first time.•Mpg-C3N4 is more suitable than g-C3N4 to fabricate the immunosensor.•Mpg-C3N4 possesses relatively large specific surface area and abundant active sites.•The immonusensor realized the sensitive detection of ALVs-J.The rapid and sensitive detecting technique for subgroup J of avian leukosis viruses (ALVs-J) needs to be developed as soon as possible in order to not only reduce economic losses but also ensure the food safety. In this paper, a novel electrochemical immunosensor was built based on mesoporous graphitic carbon nitride (mpg-C3N4). Mpg-C3N4 was used as the sensor platform to bond with the primary antibodies (Ab1). The compound of thionine and mpg-C3N4 (Th-mpg-C3N4) was synthesized for the first time to serve as the electroactive probe as well as the carrier of secondary antibodies (Ab2). Compared to bulk g-C3N4, mpg-C3N4 possesses larger specific surface area, smaller electrochemical resistance and abundant active sites. So the proposed electrochemical immunosensor exhibited amplified detective signals which realized the sensitive detection of ALVs-J. Under the opitimized conditions, the immunosensor exhibited outstanding analytical performance for the detection of ALVs-J whose titer ranged from 102.08 to 104.0 TCID50/mL (TCID50: 50% tissue culture infective dose) with a low detection limit of 120 TCID50/mL (S/N = 3). The sensitivity of the immnosensor was 6.15 μA/(TCID50/mL). This high sensitive immunosensor also displayed good selectivity, reproducibility and stability. Last but not least, this new strategy may be of great promise for clinic application in the future.

•Photoactive W-Bi2S3 composites were synthesized in aqueous system without organic additives.•The photoelectrode was fabricated onto ITO based on W-Bi2S3/PTBA heterojunction.•PTBA rendered PEC sensor with enhanced photocurrent and biologically recognition sites.•The proposed PEC sensor depicted high sensitivity and reproducibility for ALVs-J assayA novel photoelectrochemical (PEC) analyzing platform was fabricated based on tungsten-doped Bi2S3 (W-Bi2S3) composite and electropolymerized poly(thiophenyl-3-boronic acid) (PTBA) for detecting subgroup J of avian leukosis virus (ALVs-J). W-Bi2S3 composite was synthesized using a facile hydrothermal method without any organic reagents. Benefiting from the appropriate energy level cascade between PTBA and W-Bi2S3, the PTBA/W-Bi2S3/ITO electrode exhibited improved PEC performance. Based on the reaction between boric acid and sialic acid on the surface of target virus, boronic acids were used as probing receptors for capturing ALVs-J. Alkaline phosphatase assembled on the modified electrode surface was used to catalyze the hydrolysis of ascorbic acid 2-phosphate in situ producing ascorbic acid for electron donating. The proposed PEC sensor for ALVs-J assay showed a wide linear range, high sensitivity and lower detection limit. This method provides a rapid, effective and reusable platform for screening the ALVs-J-infected poultry.A reusable and effective signal-on photoelectrochemical sensing platform for ALVs-J discrimination is constructed based an enhanced photoelectrode with the hierarchical charge transport cascade, by successively organizing W-doped Bi2S3 nanostructures and electropolymerized poly(thiophenyl-3-boronic acid).

A new nonenzymatic electrochemical sensor was developed for sensitive detection of methyl parathion based on graphene nanosheets (GNs)/gadolinium Prussian Blue analogue (gadolinium hexacyanoferrate, GdHCF) modified glassy carbon electrode. The new sensor combined the individual properties of GNs (high conductivity and adsorption affinity) and GdHCF (high surface area and special catalytic activity), and realized efficient enrichment and electrochemical stripping voltammetric detection of methyl parathion. Under optimum conditions, the reduction current was proportional to methyl parathion concentration over the range from 0.008 to 10 μM with a detection limit of 1 nM. The sensor displayed high sensitivity, acceptable stability and selectivity, and realized reliable quantification of methyl parathion in practical environment samples.

A new nonenzymatic electrochemical sensor was developed for sensitive detection of methyl parathion based on graphene nanosheets (GNs)/gadolinium Prussian Blue analogue (gadolinium hexacyanoferrate, GdHCF) modified glassy carbon electrode. The new sensor combined the individual properties of GNs (high conductivity and adsorption affinity) and GdHCF (high surface area and special catalytic activity), and realized efficient enrichment and electrochemical stripping voltammetric detection of methyl parathion. Under optimum conditions, the reduction current was proportional to methyl parathion concentration over the range from 0.008 to 10 μM with a detection limit of 1 nM. The sensor displayed high sensitivity, acceptable stability and selectivity, and realized reliable quantification of methyl parathion in practical environment samples.