RESUMO
The direct and rapid conversion of abundant and cheap elemental sulfur into fluorescent sulfur quantum dots (SQDs) at room temperature is a critical and urgent challenge. Conventional synthesis methods require high temperatures, high pressures, or specific atmospheric conditions, making them complex and impractical for real applications. Herein, we propose a simple method for synthesizing SQDs simply by adding H2O2 to an elemental sulfur-ethylenediamine (S-EDA) solution at room temperature. Remarkably, within a mere 10 min, SQDs with a photoluminescence quantum yield of 23.6 % can be obtained without the need for additional steps. A comprehensive analysis of the mechanism has demonstrated that H2O2 is capable of converting Sx2- ions generated in the S-EDA solution into zero-valent sulfur atoms through oxidation. The obtained SQDs can be utilized as a fluorescent probe for detection of tetracycline (TC) and Ca2+ ions with the limit of detection (LOD) of 0.137 µM and 0.386 µM respectively. Moreover, we have developed a sensitive logic gate sensor based on SQDs, harnessing the activated cascade effect to create an intelligent probe for monitoring trace levels of TC and Ca2+ ions. This paper not only presents a viable approach for ultrafast and scalable synthesis of SQDs at room temperature, but also contributes to the efficient utilization of elemental sulfur resources.