Construction of a fluorescence switch sensor of Mn doped AgInS2 2 quantum dots for the detection of Fe (III) and ascorbic acid

The convenience and high efficiency of recently developed I-III-VI group AgInS2 2 (AIS) fluorescence sensors have garnered considerable attention. In this study, glutathione (GSH) was employed as a stabilizer to synthesize Mn doped AgInS2 2 quantum dots (Mn-AIS QDs) via a one-step hydrothermal method at a lower temperature. The resultant samples displayed favorable photoluminescent characteristics and excellent water dispersibility. The photoluminescence of Mn-AIS QDs is quenched by Fe (III) via a photo-induced electron transfer mechanism (PET), and this quenching can be reversed by ascorbic acid (AA) as a result of the redox reaction between the MnAIS-Fe (III) complex and AA. Utilizing the on-off-on fluorescence principle, a fluorescence switch sensor based on Mn-AIS QDs was developed for the detection of Fe (III) and AA. The linear range for the detection of Fe (III) using the Mn-AIS QDs sensor was established to be 0.03-120 mu M, with a detection limit (LOD) of 0.16 nM. For the detection of AA within the Mn-AIS-Fe (III) system, the linear range spanned from 0.05 to 180 mu M, with a LOD of 0.031 mu M. Both Mn-AIS and Mn-AIS-Fe (III) demonstrated robust anti-interference properties, facilitating the accurate detection of Fe (III) in tap water and AA in vitamin C tablets. This approach is notable for its simplicity, cost-effectiveness, and considerable potential for application in the creation of innovative biological and environmental sensors.