Chemiluminescence Resonance Energy Transfer-Based Detection for Microchip Electrophoresis

摘要

Since the channels in micro- and nanofluidic devices arenextremely small, a sensitive detection is required followingnmicrochip electrophoresis (MCE). This work describes anhighly sensitive and yet universal detection scheme basednon chemiluminescence resonance energy transfer (CRET)nfor MCE. It was found that an efficient CRET occurrednbetween a luminol donor and a CdTe quantum dot (QD)nacceptor in the luminol-NaBrO-QD system and that it wasnsensitively suppressed by the presence of certain organicncompounds of biological interest including biogenic aminesnand thiols, amino acids, organic acids, and steroids. Thesenfindings allowed developing sensitive MCE-CL assays fornthe tested compounds. The proposed MCE-CL methodsnshowed desired analytical figures of merit such as a widenconcentration range of linear response. Detection limitsnobtained were ∼10-9 M for biogenic amines includingndopamine and epinephrine and ∼ 10-8 M for biogenicnthiols (e.g., glutathione and acetylcysteine), organicnacids (i.e., ascorbic acid and uric acid), estrogens, andnnative amino acids. These were 10-1000 times morensensitive than those of previously reported MCE-basednmethods with chemiluminescence, electrochemical, ornlaser-induced fluorescence detection for quantifyingncorresponding compounds. To evaluate the applicabilitynof the present MCE-CL method for analyzing realnbiological samples, it was used to determine aminonacids in individual human red blood cells. Nine aminonacids, including Lys, Ser, Ala, Glu, Trp, etc., werendetected. The contents ranged from 3 to 31 amol/cell.nThe assay proved to be simple, quick, reproducible,nand very sensitive.