title: Aptamer/Au nanoparticles/cobalt sulfide nanosheets biosensor for 17β-estradiol detection using a guanine-rich complementary DNA sequence for signal amplification.
abstract: We have developed a sensitive sensing platform for 17β-estradiol by combining the aptamer probe and hybridization reaction. In this assay, 2-dimensional cobalt sulfide nanosheet (CoS) was synthesized by a simple hydrothermal method with L-cysteine as sulfur donor. An electrochemical aptamer biosensor was constructed by assembling a thiol group tagged 17β-estradiol aptamer on CoS and gold nanoparticles (AuNPs) modified electrode. Methylene blue was applied as a tracer and a guanine-rich complementary DNA sequence was designed to bind with the unbound 17β-estradiol aptamer for signal amplification. The binding of guanine-rich DNA to the aptamer was inhibited when the aptamer captured 17β-estradiol. Using guanine-rich DNA in the assay greatly amplified the redox signal of methylene blue bound to the detection probe. The CoS/AuNPs film formed on the biosensor surface appeared to be a good conductor for accelerating the electron transfer. The method demonstrated a high sensitivity of detection with the dynamic concentration range spanning from 1.0×10(-9) to 1.0×10(-12) M and a detection limit of 7.0×10(-13) M. Besides, the fabricated biosensor exhibited good selectivity toward 17β-estradiol even when interferents were presented at 100-fold concentrations. Our attempt will extend the application of the CoS nanosheet and this signal amplification assay to biosensing areas.
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China. Electronic address: kejinghuang@163.com.
authors.forename: Ke-Jing
authors.initials: KJ
authors.lastname: Huang
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Liu
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
authors.forename: Ji-Zong
authors.initials: JZ
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
authors.forename: Jun-Tao
authors.initials: JT
authors.lastname: Cao
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
authors.forename: Yan-Ming
authors.initials: YM
authors.lastname: Liu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D003035:Cobalt / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D018076:DNA, Complementary / Q000737:chemistry* / Q000235:genetics; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004958:Estradiol / Q000032:analysis*; D006046:Gold / Q000737:chemistry; D006147:Guanine / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D052157:Aptamers, Nucleotide; D018076:DNA, Complementary; D003035:Cobalt; D004958:Estradiol; D006147:Guanine; D006046:Gold; C027875:cobaltous sulfide
keywords: 17β-Estradiol; Au nanoparticles; Cobalt sulfide nanosheet; Guanine-rich complementary DNA sequence; Methylene blue; Signal amplification