Direct photoconjugation multi-wall carbon nanotube-based immunosensor platform for clenbuterol determination.

This study reports the development of a carbon nanotube-based potentiometric sensor for the selective and cost-effective detection of clenbuterol. The sensor design depends on specific molecular recognition between clenbuterol and an anti-clenbuterol antibody covalently immobilized onto a photosensitive amino acid-modified multi-walled carbon nanotube (MWCNT) platform. This functional nanomaterial enabled the direct conjugation of the antibody-crosslinked electrode surface. An anti-clenbuterol antibody-bound MWCNT was used as the indicator electrode. An Ag/AgCl electrode was used as the reference electrode. The immunopotentiometric sensor exhibited a rapid response (1 min), a broad linear detection range from 1.0 × 10-11 M to 1.0 × 10-5 M, and an excellent low detection limit of 4.83 × 10-12 M. The operational lifetime was extended to 36 weeks, with pH 6.0 identified as the optimal working condition. The proposed immunopotentiometric sensor offers high selectivity, low detection limits, cost-effectiveness, and label-free detection, making it a promising tool for clenbuterol monitoring.