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.
|Number of pages||4|
|Publication status||Published - 21 Feb 2012|
Scopus Subject Areas
- Analytical Chemistry
- Environmental Chemistry