Yunlei Zhou,Yue Wang,Shurong Li,Xi Fang,Huanshun Yin,Po Wang,Shiyun Ai
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.
Mengjia Zhou,Ziyan Cui,Yun Liu,Dan Wang,Yanzhou Li,Junwei Zhao,Wenwu You
In this study, a highly sensitive photoelectrochemical (PEC) immunosensor for the detection of carcinoembryonic antigen (CEA) utilizing core-sheath-type TiO 2 @NH 2 -MIL-125(Ti) nanocone array heterostructures was developed. The immunosensor was constructed by depositing NH 2 -MIL-125(Ti) as a sheath onto FTO/TiO 2 nanocones through seed-assisted solvothermal synthesis. The TiO 2 @NH 2 -MIL-125(Ti) heterostructure showcased superior PEC detection capabilities for CEA, leveraging the quantum and tip effects of the TiO 2 nanocones along with the broad-spectrum absorption of NH 2 -MIL-125(Ti), which collectively enhanced light utilization and photoelectric conversion efficiency. The internal electric field at the NH 2 -MIL-125(Ti)/TiO 2 interface enabled efficient photogenerated electron transfer, eliminating the need for external bias and enhancing photocurrent. The antibody-functionalized surface effectively captured CEA, resulting in a clear decrease in photocurrent. Under optimized conditions, the immunosensor exhibited a linear response to CEA in the range of 0.1 pg/mL to 100 ng/mL with a remarkable detection limit of 0.54 fg/mL. The developed PEC immunosensor demonstrated high stability and excellent reproducibility, providing an innovative strategy for the development of sensitive photoactive heterojunction materials for biomarker immunosensing applications.
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