Highly sensitive, label-free detection of 2,4-dichlorophenoxyacetic acid using an optofluidic chip

• Main Authors: Feng, Xueling, Zhang, Gong, Chin, Lip Ket, Liu, Ai Qun, Liedberg, Bo
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; Optofluidic Chip; Microring Resonator
• Online Access: https://hdl.handle.net/10356/139094
• Institution: Nanyang Technological University

A highly sensitive approach for rapid and label-free detection of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using an optofluidic chip is demonstrated. The optofluidic chip is prepared by covalent immobilization of 2,4-D-bovine serum albumin (2,4-D-BSA) conjugate to an integrated microring resonator. Subsequent detection of 2,4-D carried out in a competitive immunoreaction format enables selective detection of 2,4-D in different types of water samples, including bottled, tap, and lake water, at a limit of detection (LOD) of 4.5 pg/mL and in a quantitative range of 15-105 pg/mL. The microring resonator-based optofluidic chip is reusable with ultrahigh sensitivity that offers real-time and on-site detection of low-molecular-weight targets for potential applications in food safety and environmental monitoring.