Electrochemiluminescence resonance energy transfer between methylene blue and Ru(bpy)32+-doped silica nanoparticles and its application in “turn-on” detection of glucose
Electrochemiluminescence (ECL) donor of Ru(bpy)32+-doped silica nanoparticles (RuSiNPs) and acceptor of methylene blue (MB) is developed to achieve electrochemiluminescence resonance energy transfer (ECRET) using the overlap of ECL emission of RuSiNPs with absorption of MB. Owing to ECRET from RuSiNPs to MB, ECL of RuSiNPs is quenched by MB. MB is an oxidation of glucose catalysed by MB only under alkaline condition. MB with blue color is reduced to colourless methylene white by glucose accompanied by the disappearance of the absorbance at 650 nm. Accordingly ECRET is inhibited after the addition of glucose to RuSiNPs and MB mixture. Therefore ECL “turn-on” detection of glucose is achieved via the proposed ECRET strategy. The proposed ECRET method exhibits high sensitivity for glucose detection with limit of detection (LOD) of 85.4 nM, selectivity towards other metal ions, anions, dopamine or uric acid, and fast response within 5 min. It is also successfully applied in human serum detections and the average recoveries of 99.33 %, 99.73 % and 100.07 % are obtained. It widens the application of ECRET in bioanalysis.