Electrogenerated chemiluminescence detection of trace level pentachlorophenol using carbon quantum dots

Abstract

Pentachlorophenol (PCP) is an environmental pollutant of serious concern due to its high toxicity and long persistence property. Fast and sensitive detection of PCP is therefore of great interest. In this work, carbon quantum dots (QDs) are synthesized by hydrothermal reaction, and characterized by fluorescence spectrophotometer, fourier transform infrared (FT-IR) spectroscopy, UV/vis/NIR spectrophotometer and scanning electron microscopy (SEM). The carbon QDs show stable and intensive electrogenerated chemiluminescence (ECL) in the presence of the coreactant S2O8(2-). Under the scanning potential of -1.2 to 0.5 V, PCP reacts with the excited C˙(-), resulting in a decrease in ECL. The detection of trace level PCP is therefore achieved using the carbon QDs and Pt working electrode. Parameters that may affect the ECL intensity including the pH of solution, ionic strength, concentrations of coreactant and carbon QDs are optimized. Under the optimal conditions, a detection limit of 1.3 × 10(-12) g L(-1) is achieved with a linear range of 10 pg L(-1)∼1.0 μg L(-1).

Enhanced electrochemiluminescence sensing platform using nitrogen-doped graphene as a novel two-dimensional mat of silver nanoparticles

“…The detection of PCP has been reported based on its quenching effect on the ECL of carbon quantum dots resulting from an electrontransfer process [18,19]. Thus, the ECL quenching mechanism of PCP here might be attributed to electron transfer annihilation of SO 4 •À .…”

A highly stable and effective electrochemiluminescence platform of copper oxide nanowires coupled with graphene for ultrasensitive detection of pentachlorophenol

“…In our case, weak ECL response was observed for CuO NWs without the coreactant S 2 O 8 2− while the presence of S 2 O 8 2− remarkably increased the ECL intensity ( Fig. 2A), implying that S 2 O 8 2− plays an important role for the ECL of CuO NWs, and the ECL process can be speculated to be dominated by the coreactant mechanism [23,24,35]. The further increase of the ECL signal by rGO, as observed for the CuO NWs/rGO, could be attributed to the increased exposed surface areas of CuO NWs due to rGO supporting (Fig.…”

“…In recent years, particular interest has been moved from traditional ECL materials, such as Ru(bpy) 3 2+ [17] to nanocrystals (NCs) or quantum dots (QDs) (e.g., CdS NCs and Si QDs) [18,19] since the latter possess enhanced ECL efficiencies due to the quantum confinement effect and controllable surface chemistry. The NCs/QDs-based ECL studies, however, still suffer from some limitations, such as high toxicity of the most used ECL species (e.g., CdTe, CdS, and CdSe) [18,[20][21][22], poor stability, and non-recycle of the ECL species in solutions [22][23][24]. Thus it is highly desirable to develop new platforms with low-toxic or non-toxic ECL species, outstanding stability and excellent recyclability for ECL detection.…”

“…(C) ECL emission from CuO NWs/rGO with 0.1 mol L −1 S2O8 2− under continuous 35 cycles of cyclic voltammetry. at the applied negative potential, which might inhibit the reduction of S 2 O 8 2− , while in a basic solution, the intermediate SO 4 •− wouldbe scavenged by OH •− , resulting in a decrease in the ECL intensity[24]. The effect of S 2 O 8 2− concentration is shown inFig.…”

Determination of pentachlorophenol by anodic electrochemiluminescence of Ru(bpy)32+ based on nitrogen-doped graphene quantum dots as co-reactant

“…Among them, the ECL of GQDs, especially the heteroatom-doped GQDs, have attracted wide attention owing to their unique features, including good water solubility, low toxicity and better edge effect. 17 For example, Li et al 18 built a novel ECL sensor based on carbon quantum dots with S 2 O 8 2À as co-reactant to detect PCP, achieving a low limit of detection. Similarly, utilizing nitrogen-doped GQDs (NGQDs) as luminophor, Du et al 19 constructed a cathodic ECL sensor for the detection of PCP.…”