Portable arginine sensing on polyvinyl alcohol membrane based on aggregation-induced emission enhancement of carbon dots

Carbon dots (CDs) were highly promised nanomaterials for application in food analysis, owing to their exceptional optical properties, superior photostability, and negligible biological toxicity. N-doped CDs (NCDs) were synthesized via a straightforward hydrothermal method utilizing folic acid as only one precursor material. NCDs exhibited deep blue fluorescence under an ultraviolet lamp with a quantum yield (QY) of 14.54 %. In the presence of arginine (Arg), there was a noticeable redshift of 10 nm in the maximum emission wavelength of NCDs, accompanied by fluorescence transition from dark blue to bright blue. The QY of NCDs was 16.71 % in the presence of Arg. In other words, NCDs showed aggregation-induced emission enhancement (AIEE) in the presence of Arg. The fluorescence enhancement exhibited a strong linear correlation with Arg concentration within the range of 0–300 μM, and the limit of detection was 0.31 μM. Furthermore, to facilitate Arg detection, a portable Arg sensor was developed using a polyvinyl alcohol membrane-assisted design. The sensor demonstrated satisfactory performance in detecting Arg in real samples. These findings highlighted the versatile capabilities of NCDs with AIEE properties, paving the way for their potential applications in food analysis.