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

Abstract

A self-powered temperature\nsensor based on Seebeck effect transduction\nwas designed for photothermal–thermoelectric coupled immunoassay\nof α-fetoprotein (AFP). In this system, glucose oxidase (GOx)-conjugated\ndetection antibody was first captured onto the microplate by target-induced\nsandwich-type immunoreaction. Thereafter, the as-generated hydrogen\nperoxide via the GOx–glucose system oxidized 3,3′,5,5′-tetrametylbenzidine\n(TMB) into photothermal product oxidized TMB (ox-TMB). Under near-infrared\n(NIR) laser irradiation, the temperature change of ox-TMB was read\nout in an electrical signal by the flexible thermoelectric module\nin a 3D-printed integrated detection device. Under optimal conditions,\nthe photothermal–thermoelectric coupled immunoassay exhibited\na limit of detection of 0.39 ng mL^–1 AFP over a\ndynamic linear range from 0.5 to 60 ng mL^–1. Impressively,\nsuch a strategy presented herein offers tremendous potentials for\napplying many other high-efficiency thermoelectric materials in ultrasensitive\nbiosensors.