Aldehydes and ketone sensitive fluorescence sensor constructed by hydroxylamine hydrochloride and carbon quantum dots for baijiu recognition.

In this study, a three-channel fluorescence sensor was developed by integrating hydroxylamine hydrochloride (NH₂OH·HCl) with three novel carbon quantum dots (CDs: m-AP@CDs, m-PD@CDs, and o-PD@CDs) to enable the identification of 16 aldehydes, ketones, and diverse baijiu samples. The three-channel sensor was first evaluated for its fluorescence response to aldehydes and ketones, revealing a response intensity hierarchy, ranked as follows: aromatic aldehydes, aliphatic aldehydes, diketones, aromatic ketones, monoketones, and acetal. With the aid of the Linear Discriminant Analysis (LDA) model, all 16 analytes at even low concentrations (2.0 × 10 - 2 mmol/L) could achieve 100 % discrimination accuracy. Furthermore, the spliced spectra of the sensor combined with the Partial Least Squares Regression (PLSR) model was used to accurately quantify 16 kinds of aldehydes and ketones in the range of 2.0 × 10 - 10 mmol/L. What's more, variations in aldehyde/ketone content across baijiu samples could generate cross-responses with the three-channel sensor, which ensured the sensor could accurately distinguish different flavors, brands and quality baijiu combined with the LDA model, underscoring its potential for rapid, on-site quality control and counterfeit detection in the baijiu industry.