Room temperature, ultrafast and one-step synthesis of highly fluorescent sulfur quantum dots probe and their logic gate operation.

[Display omitted] • Room temperature and ultrafast synthesis of sulfur quantum dots (SQDs) is presented. • The conversion of elemental sulfur to fluorescent SQDs can be completed in 10 min. • The prepared SQDs have a photoluminescence quantum yield as high as 23.6%. • The utilization of SQDs to sensitively detect tetracycline and Ca2+ ions is reported. • A sensitive logic gate sensor based on SQDs is constructed. 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 H 2 O 2 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 H 2 O 2 is capable of converting S x 2− 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. [ABSTRACT FROM AUTHOR]