Vanillin-Catalyzed highly sensitive luminol chemiluminescence and its application in food detection.

Abstract

Among various chemiluminescence (CL) systems, luminol-H2O2 system is used extensively due to its cheapness and sensitivity. Herein, 4-hydroxy-3-methoxybenzaldehyde, known as vanillin, was firstly found to be able to catalyze H2O2 very efficiently to produce •OH and O2•-, which can be used to enhance the CL of luminol-H2O2 as Co+. In alkaline aqueous solution, vanillin catalyzed the dissociation of H2O2 into active •OH and O2•- radicals and accelerated luminol-H2O2 reaction to emit strong CL signal. Combining the stabilizing function of β-CD, CL intensity of luminol-H2O2 was enhanced further. Thus, dual-signal amplification of luminol-H2O2 chemiluminescence based on the catalyzing function of vanillin and the stabilizing function of β-CD was proposed and its mechanism was explored deeply in the manuscript. Interestingly, vanillin is a highly prized flavor compound broadly used as food additive, however, the excessive intake of vanillin is harmful to human and thus the determination of vanillin is very important. On the basis of the luminol-β-CD-H2O2/vanillin reaction, a low-cost, rapid and simple CL sensor has been established to detect vanillin. The sensor was able to detect vanillin in the range of 1.0μM∼75μM with a detection limit of 0.89μM (S/N=3). It can also be used for CL imaging detection with satisfactory results.