CO-detecting torch using carbon nanodots

Abstract

Carbon monoxide (CO), a common environmental contaminant, is responsible for a significant proportion of accidental poisonings and fatalities reported globally each year. Accurate detection and regulation of carbon monoxide in both residential and industrial settings are critical to mitigate the risk of severe health complications in humans due to its hazardous features and widespread sources. CO is odorless, colorless, tasteless, and non-irritating, which makes it particularly challenging to identify without a specialized tool. In this study, we have designed a portable sensing device utilizing N-CQDs for the real-time detection of atmospheric CO with fluorescence quenching and visual detection. In this detection process, we elucidated the fluorescence quenching mechanism of N-CQDs upon binding with CO (binding affinity 9.2 × 10-4 M-1) with a detection limit of 0.07 μM (linear range between 4.77 and 41.23 μM). Several techniques, including HRTEM, DLS, EDX, FT-IR, XPS, UV-vis spectroscopy, fluorescence spectroscopy, and fluorescence lifetime decay, have also been employed to elucidate the quenching mechanism.