Antibody

Chemistry

Materials science

Chromatography

Optoelectronics

Biochemistry

Thermoelectric effect

Physics

Photothermal therapy

Glucose oxidase

Detection limit

Nanotechnology

Biology

Linear range

Seebeck coefficient

Analytical Chemistry (journal)

Immunoassay

Biosensor

Immunology

Thermodynamics

Analytical Chemistry

A self-powered temperature sensor based on Seebeck effect transduction was designed for photothermal-thermoelectric coupled immunoassay of α-fetoprotein (AFP). In this system, glucose oxidase (GOx)-conjugated detection antibody was first captured onto the microplate by target-induced sandwich-type immunoreaction. Thereafter, the as-generated hydrogen peroxide via the GOx-glucose system oxidized 3,3',5,5'-tetrametylbenzidine (TMB) into photothermal product oxidized TMB (ox-TMB). Under near-infrared (NIR) laser irradiation, the temperature change of ox-TMB was read out in an electrical signal by the flexible thermoelectric module in a 3D-printed integrated detection device. Under optimal conditions, the photothermal-thermoelectric coupled immunoassay exhibited a limit of detection of 0.39 ng mL-1 AFP over a dynamic linear range from 0.5 to 60 ng mL-1. Impressively, such a strategy presented herein offers tremendous potentials for applying many other high-efficiency thermoelectric materials in ultrasensitive biosensors.

Self-Powered Temperature Sensor with Seebeck Effect Transduction for Photothermal–Thermoelectric Coupled Immunoassay