Label-free aptamer-based electrochemical impedance biosensor for 17β-estradiol

• Published in: Analyst (London) Vol. 137; no. 4; pp. 819 - 822
• Main Authors: Lin, Zhenyu, Chen, Lifen, Zhang, Guiyun, Liu, Qida, Qiu, Bin, Cai, Zongwei, Chen, Guonan
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 21.02.2012
• Subjects: Analytical chemistry; Aptamers, Nucleotide - chemistry; Biological and medical sciences; Biosensing Techniques - methods; Biosensors; Biotechnology; Chemistry; Dielectric Spectroscopy - methods; Electrochemical methods; Electrochemical Techniques - methods; Electrochemistry - methods; Electrodes; Electron transfer; Estradiol - urine; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General, instrumentation; Gold; Gold - chemistry; Human; Humans; Limit of Detection; Methods. Procedures. Technologies; Sensitivity and Specificity; Stability; Urine; Various methods and equipments; Human; Urine; Gold; Stability; Electrochemical method; Immobilization; Electron transfer; Selectivity; Concentration; Chemical sensor; Probe; Estradiol; Design; Resistance; Biosensor; Detection limit; Lead; Impedance; Electrochemical impedance spectroscopy
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c1an15856b

A novel aptamer-based label-free electrochemical impedance spectroscopy biosensor for 17β-estradiol has been fabricated. The aptamers were firstly immobilized on the gold electrode through Au-S interaction; the aptamer probe was then bound with the addition of 17β-estradiol to form the estradiol/aptamer complex on the electrode surface. This leads to a significantly larger interfacial electron transfer resistance than that without the addition of 17β-estradiol. The change in the resistance had a linear relationship with 17β-estradiol concentration in the range of 1.0 × 10(-8) to 1.0 × 10(-11) mol L(-1), with a detection limit of 2.0 × 10(-12) mol L(-1). The biosensor showed high selectivity to 17β-estradiol and good stability. The designed biosensor has been applied to detect 17β-estradiol in human urine with satisfactory results.