Microfluidic chip based chemiluminescence detection of L-phenylalanine in pharmaceutical and soft drinks

• Published in: Food chemistry 2012-11, Vol.135 (1), p.57-62
• Main Authors: Kamruzzaman, Mohammad, Alam, Al-Mahmnur, Kim, Kyung Min, Lee, Sang Hak, Kim, Young Ho, Kim, Gyu-Man, Dang, Trung Dung
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chemiluminescence; Chip formation; Chips; CuSO4; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; L-phenylalanine; Luminol; Methods of analysis, processing and quality control, regulation, standards; Microchannels; Microfluidic chip; Microfluidics; Non alcoholic beverage industries and mineral waters; Pharmaceuticals; Silicone resins; Soft drinks
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.04.062

► We presented a microfluidic chip based CL system to determine L-phenylalanine (L-PA). ► It is based on the enhanced CL signal of luminol–H2O2–Cu2+ in the presence of L-PA. ► It gives high sensitivity with small sample volume and short analytical time. ► It shows good linearity over the L-PA concentration in the range of 1.5–120nM. ► The method is easily applicable to determine L-PA at low concentration in food. A sensitive chemiluminescence (CL) method on chip coupled with microfluidic system has been reported for the determination of L-phenylalanine (L-PA). A microfluidic chip device with the detection chamber capable of fast sensing light emitted from the luminol and hydrogen peroxide CL reaction catalyzed by copper sulphate was fabricated for the determination of L-PA. The microfluidic chip was fabricated by a soft-lithographic procedure using polydimethyl siloxane (PDMS). The fabricated PDMS microfluidic chip had four inlet microchannels for introducing the sample, chemiluminescent reagent, Cu(II), and oxidant, and a 500μm wide, 250μm deep, and 82mm long microchannel. The detection was based on the enhancement effect of L-PA on the CL signals of luminol–H2O2–Cu2+ system in an alkaline medium. The CL intensity of the system was enhanced linearly with the concentration of L-PA in the range of 1.5×10−9–1.2×10−7molL−1. The limit of detection was found to be 2.4×10−10molL−1 with the relative standard deviation of 1.8%. The presented method offers a simple, rapid and easy to handle analytical technique in terms of sensitivity, dynamic range and low detection limit for the determination of L-PA in diet soft drinks and pharmaceutical injection samples.