A novel piezoelectric quartz micro-array immunosensor based on self-assembled monolayer for determination of human chorionic gonadotropin

• Published in: Biosensors & bioelectronics 2004-02, Vol.19 (7), p.711-720
• Main Authors: Zhang, Bo, Mao, Qiongguo, Zhang, Xue, Jiang, Tianlun, Chen, Ming, Yu, Fan, Fu, Weiling
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Chorionic Gonadotropin - blood; Chorionic Gonadotropin - urine; Coated Materials, Biocompatible - chemical synthesis; Coated Materials, Biocompatible - chemistry; Equipment Design; Equipment Failure Analysis; Fundamental and applied biological sciences. Psychology; Human chorionic gonadotropin (hCG); Humans; Immunoassay - instrumentation; Immunoassay - methods; Immunosensor; Methods. Procedures. Technologies; Piezoelectric quartz crystal; Protein Array Analysis - instrumentation; Protein Array Analysis - methods; Quartz; Reproducibility of Results; Self-assembled monolayer (SAM); Sensitivity and Specificity; Various methods and equipments
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/S0956-5663(03)00260-4

A novel multi-channel 2×5 model of piezoelectric quartz micro-array immunosensor has been developed for quantitative detection of human chorionic gonadotropin (hCG) in serum or urine samples. Every crystal unit of the fabricated piezoelectric hCG micro-array immunosensor can oscillate independently without interfering each other. A 2×5 model of micro-array immunosensor as compared with a one-channel immunosensor can provide eight times higher detection speeds for hCG assay. The anti-hCG antibody is deposited on the gold electrode’s surface of 10 MHz quartz AT-cut crystal by self-assembled technique using sulfosuccinimidyl 6-[3′-(2-pyridyldithio) propionamido] hexanoate (Sulfo-LC-SPDP), and serves as an antibody recognizing layer. The highly ordered self-assembled monolayers (SAM) ensure well-controlled surface structure and offer many advantages to the performance of the sensor. Compared with conventional antibody immobilization methods, the amount and the reaction activity of antibody monolayer coated by the SAM binding are bigger than those by the SPA method, and less non-specific binding caused by other analytes in sample is found. Under the optimized experimental conditions, the results showed that micro-array immunosensor quantitatively detected serum or urine hCG in the range of 2.5–500 mIU/ml with high precision (CV