A novel photoelectrochemical immunosensor for N1-methyladenine detection based on BiVO4/g-C3N4 heterojunction with signal amplification of TiO2@NH2-MIL-125(Ti)

Photoelectrochemical (PEC) immunosensor was designed to detect N 1 -methyladenosine (m 1 A), where BiVO 4 /g-C 3 N 4 heterojunction was employed as photoactive material, polyamidoamine (PAMAM) and 4-carboxyphenylboronic acid (CPBA) were used as m 1 A antibody immobilization matrix, and Ti-based metal-organic framework encapsulated heterostructure of TiO 2 @NH 2 -MIL-125(Ti) was adopted as signal amplification. Due to the interaction between TiO 2 and phosphate, TiO 2 @NH 2 -MIL-125(Ti) was captured after immunoreaction between m 1 A and its antibody, which can further improve the detection sensitivity with increased PEC response. Under optimal experimental conditions, this method presented wide dynamic range (0.05–35 nM) with the low determination limit (16.7 pM, S/N = 3). This detection strategy showed good detection reproducibility, stability and selectivity. This method was applied to assess the effect of antibiotics on m 1 A content in the leaves, stems and roots of rice seedlings.