A novel fluorescence sensor film for hydroquinone based on a graphene quantum dots-nano activated carbon composite

Abstract

A novel film sensor, composed of graphene quantum dots-nano activated carbon, chitosan, and PVA, offers a simple and effective hydroquinone (HQ) detection. This film exhibits impressive HQ adsorption under ambient conditions (room temperature, pH 7, 3 h) and utilizes a readily observable fluorescence color change for quantification. Upon HQ binding, the film's fluorescence color shifts from yellow-green to blue, enabling a linear detection range of 1.0–150 mg⋅L⁻¹ based on intensity analysis of the blue component (B value). Calibration curves generated on the same day (n = 3) exhibit high precision, with standard deviations of the linear equation parameters below 0.014 and a low detection limit of 0.5 mg⋅L⁻¹. The film exhibits exceptional stability, retaining its color and performance for up to 20 days. This stability is further corroborated by recovery experiments utilizing HQ-spiked water samples at concentrations of 2.5 mg⋅L⁻¹ and 40 mg⋅L⁻¹, where recoveries of 106 % and 95 % were achieved, respectively. These results demonstrated the sensor's reliable quantification capabilities. Notably, the sensor exhibited insignificant interference from commonly co-existing substances such as ethanol, ascorbyl glucoside, arbutin, kojic acid, and methylene blue. However, Cu²⁺, Fe³⁺, and catechol did cause some interference. This versatility, coupled with its straightforward operation, makes the film sensor a promising candidate for on-site HQ detection in diverse environmental monitoring applications.