Graphene quantum dots/bisulfite assisted chemiluminescence of rhodamine B-H₂O₂ system for sensitive recognition of HCHO

A novel and powerful chemiluminescence (CL) system was developed based on the promoting effect of graphene quantum dots (GQDs)/bisulfite on rhodamine B (RB)-H₂O₂ CL reaction. GQDs were synthesized by a simple, green and affordable approach and characterized using their distinctive absorption and emission patterns. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) transmission and transmission electron microscopy (TEM) analysis were implemented for complementary studies on the structural and morphological characteristics of GQDs. The simultaneous enhancing effect of the synthesized GQDs and bisulfite on the CL emission of RB-H₂O₂ reaction provided a more strong and efficient CL system. The mechanism of CL emission was described. Furthermore, HCHO as a well-known pollutant, could selectively diminish the developed CL system. This effect was linearly proportional to HCHO concentration which turned the introduced CL system to a susceptible chemosensor for HCHO. Under the optimized operational condition, the linear changing of CL response was obtained in HCHO concentration ranges of 0.02–5 μg L⁻¹ and 5–11 μg L⁻¹, with limit of detection (LOD) and quantification (LOQ) of 6 ng L⁻¹ and 20 ng L⁻¹, respectively. Ultimately, presented CL chemosensor was served as an accurate tool for determination of formaldehyde concentration in water and wastewater samples.