The Fluorescent Detection of Glucose and Lactic Acid Based on Fluorescent Iron Nanoclusters

In this paper, a novel fluorescent detection method for glucose and lactic acid was developed based on fluorescent iron nanoclusters (Fe NCs). The Fe NCs prepared using hemin as the main raw material exhibited excellent water solubility, bright red fluorescence, and super sensitive response to hydrogen peroxide (H₂O₂). This paper demonstrates that Fe NCs exhibit excellent peroxide-like activity, catalyzing H₂O₂ to produce hydroxyl radicals (^•OH) that can quench the red fluorescence of Fe NCs. In this paper, a new type of glucose sensor was established by combining Fe NCs with glucose oxidase (GluOx). With the increase in glucose content, the fluorescence of Fe NCs decreases correspondingly, and the glucose content can be detected in the scope of 0-200 μmol·L^-1 (μM). Similarly, the lactic acid sensor can also be established by combining Fe NCs with lactate oxidase (LacOx). With the increase in lactic acid concentration, the fluorescence of Fe NCs decreases correspondingly, and the lactic acid content can be detected in the range of 0-100 μM. Furthermore, Fe NCs were used in the preparation of gel test strip, which can be used to detect H₂O₂, glucose and lactic acid successfully by the changes of fluorescent intensity.