A sensitive, label free electrochemical aptasensor for ATP detection.
A sensitive, label free electrochemical aptasensor for small molecular detection has been developed in this work based on gold nanoparticles (AuNPs) amplification. This aptasensor was fabricated as a tertiary hybrid DNA-AuNPs system, which involved the anchored DNA (ADNA) immobilized on gold electrode, reporter DNA (RDNA) tethered with AuNPs and target-responsive DNA (TRDNA) linking ADNA and RDNA. Electrochemical signal is derived from chronocoulometric interrogation of [Ru(NH(3))(6)](3+) (RuHex) that quantitatively binds to surface-confined DNA via electrostatic interaction. Using adenosine triphosphate (ATP) as a model analyte and ATP-binding aptamer as a model molecular reorganization element, the introduction of ATP triggers the structure switching of the TRDNA to form aptamer-ATP complex, which results in the dissociation of the RDNA capped AuNPs (RDNA-AuNPs) and release of abundant RuHex molecules trapped by RDNA-AuNPs. The incorporation of AuNPs in this strategy significantly enhances the sensitivity because of the amplification of electrochemical signal by the RDNA-AuNPs/RuHex system. Under optimized conditions, a wide linear dynamic range of 4 orders of magnitude (1 nM-10 microM) was reached with the minimum detectable concentration at sub-nanomolar level (0.2 nM). Those results demonstrate that our nanoparticles-based amplification strategy is feasible for ATP assay and presents a potential universal method for other small molecular aptasensors.
Li
Wang
W
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, PR China.
Nie
Zhou
Z
Xu
Xiahong
X
Shen
Qinpeng
Q
Deng
Chunyan
C
Chen
Jinhua
J
Yao
Shouzhuo
S
D000255:Adenosine Triphosphate / Q000032:analysis*; D052157:Aptamers, Nucleotide; D004563:Electrochemistry / Q000379:methods*; D006046:Gold; D053768:Metal Nanoparticles
D052157:Aptamers, Nucleotide; D006046:Gold; D000255:Adenosine Triphosphate