A fluorescent fiber pH sensor for sensitive, wide-range detection using orange-emitting silicon quantum dots

pH value plays a vital role in biochemical analysis. To achieve online analysis, a new type of fluorescent fiber sensor has been developed for real-time, wide-range pH monitoring in biological and environmental fluids. The fluorescent fiber pH sensor was facilely created by immobilizing orange-emitting silicon quantum dots onto a tapered fiber probe through a photoinduced hydrogel polymerization technique. The sensor displays a specific response to pH variations, covering an extensive dynamic range from pH 3.0 to 12.0 with a resolution of 0.06/pH. Additionally, the sensor exhibited remarkable stability, repeatability, robustness, and reversibility. Especially, its high stability to ion strength and temperature fluctuations ensures reliable performance across various physiological and physical conditions. Furthermore, successful implementations of this sensor in detecting pH levels in real serum, artificial sweat and seawater samples further validate its accuracy, practicality and versatility. Overall, this sensor offers a practical and versatile tool for sensitive, real-time pH sensing in complex fluid environments, with great potential across multiple fields.