An ultra-sensitive smartphone-integrated digital colorimetric and electrochemical Camellia sinensis polyphenols encapsulated CuO nanoparticles-based ammonia biosensor

Abstract

• An ultra-sensitive smartphone-integrated digital colorimetric CuO nanoparticles-based biosensor was developed. • CuO nanoparticles-based biosensor was used for nanomolar determination of ammonia. • The colorant biosensor was used for monitoring of food spoilage. • The colorimetric PPS-CuO NPs-based biosensor showed a high selectivity of ammonia. With advancement trends in recent studies, it has drawn considerable attention towards the development of smartphone-integrated colorimetric biosensors with a high performance, stability, and selectivity for specific detection of analytes in food safety. Herein, camellia sinensis polyphenols encapsulated CuO nanoparticles (PPS-CuO NPs) based biosensors were developed as an ultra-sensitive smartphone-integrated digital colorimetric ammonia indicator for monitoring of food spoilage. The PPS-CuO NPs were characterized using different techniques such as SEM, HRTEM, FTIR, and XRD techniques. The colorimetric and electrochemical PPS-CuO NPs-based biosensor showed a high selectivity of ammonia with a high coefficient of correlation (R 2 = 0.960), a wide concentration range of 12.5–100 µM, and a low limit of detection (LOD) of 40.6 nM. The developed smartphone-integrated colorimetric system exhibited high chemical selectivity for ammonia. Consequently, the sensing performance of PPS-CuO NPs based biosensors showed that it is a promising material for the determination of ammonia for food safety.