A Femtomolar Level and Highly Selective 17β-estradiol Photoelectrochemical Aptasensor Applied in Environmental Water Samples Analysis

Abstract

Driven by the urgent demand of determining low level of 17β-estradiol (E2) present in environment, a novel and ultrasensitive photoelectrochemical (PEC) sensing platform based on anti-E2 aptamer as the biorecognition element was developed onto CdSe nanoparticles-modified TiO2 nanotube arrays. The designed PEC aptasensor exhibits excellent performances in determination of E2 with a wide linear range of 0.05-15 pM. The detection limit of 33 fM is lower than the previous reports. The aptasensor manifests outstanding selectivity to E2 while used to detect seven other endocrine disrupting compounds that have similar structure or coexist with E2. The superior sensing behavior toward E2 can be attributed to the appropriate PEC sensing interface resulting from the preponderant tubular microstructure and excellent photoelectrical activity, the large packing density of aptamer on the sensing interface, as well as the high affinity of the aptamer to E2. The PEC aptasensor was applied successfully to determine E2 in environmental water samples without complicate sample pretreatments, and the analytical results showed good agreement with that determined by HPLC. Thus, a simple and rapid PEC technique for detection low level of E2 was established, having promising potential in monitoring environmental water pollution.

Photoelectrochemical aptasensing

“…Similarly, NH 2 -groups have also been covalently bound to − CHO groups in a number of PEC aptasensing [63,67,71,76]. To facilitate the covalent binding, some versatile reagents including chitosan (with numerous -NH 2 groups), silanization chemicals (e.g.…”

Aptamer-Based Technology for Food Analysis

“…Yildirim et al [118] developed an aptamer-based optical biosensor for rapid and sensitive detection of 17β-estradiol in water samples, with a detection limit of 0.6 ng/mL. Similarly, based on anti-17β-estradiol aptamer, Fan et al [119] developed a novel and ultrasensitive photoelectrochemical (PEC) sensor for detection low level of 17β-estradiol in water samples, with a detection limit of 33 fM.…”

A highly sensitive photoelectrochemical detection of perfluorooctanic acid with molecularly imprined polymer-functionalized nanoarchitectured hybrid of AgI–BiOI composite

“…It should be noted that photoactive materials play a crucial role in the performance of PEC sensors. Owing to the strong oxidizing power, photostability, and environmental benignity, various titanium dioxide (TiO 2 )-based visible-light-responsive photoactive composites (e.g., CdSe x Te 1 À x -sentisized TiO 2 , metal-doped TiO 2 , polymerhybridized TiO 2 and CdTe-cosensitized TiO 2 /CdS:Mn) for PEC sensing have been explored (Kang et al, 2010;Li et al, 2014;Wang et al, 2013;Fan, L.F., et al, 2014). Despite these advances, the relatively sophisticated fabrication methods as well as tedious coupling procedures have seriously hampered their applications.…”