One-step hydrothermal synthesis of WS quantum dots as fluorescent sensor for sensitive and selective recognition of hemoglobin and cardiac biomarker myoglobin.

Transition metal dichalcogenide (TMD) dots exhibit excellent photoluminescence performance due to the quantum confinement effect and edge effect, and are extensively applied in electronic and optical devices, sensors, catalysis, and bioimaging. In this work, WS quantum dots (WS QDs) were prepared under a simple one-step hydrothermal method by optimizing the reaction conditions, and a quantum yield of 11.23% was achieved. The as-prepared WS QDs possess good photo-bleaching resistance, salt tolerance, and pH stability. The fluorescence investigations showed that the WS QDs acted as a highly efficient fluorescent sensor to detect hemoglobin (Hb) and cardiac biomarker myoglobin (Myo). The linear range was 1-600 μg/mL for Hb and 0.01-120 μg/mL for Myo, with detection limits as low as 260 and 7.6 ng/mL, respectively. Importantly, the WS QDs were used to determine the Hb/Myo content in human blood/serum samples, with satisfactory results, indicating that this technique holds promise for application in clinical diagnosis associated with Hb/Myo levels. To the best of our knowledge, this is the first example of TMD QDs without any modification as a fluorescent sensor for detecting Hb and Myo simultaneously.