title: Small organic molecules detection based on aptamer-modified gold nanoparticles-enhanced quartz crystal microbalance with dissipation biosensor.
abstract: Small molecules are difficult to detect by the conventional quartz crystal microbalance with dissipation (QCM-D) technique directly because the changes in frequency resulting from the binding processes of small biomolecules are often small. In the current study, an aptamer-based gold nanoparticles (AuNPs)-enhanced sensing strategy for detection of small molecules was developed. The QCM crystal was first modified with a layer of thiolated linker DNA, which can be partly base-paired with the detection part containing the adenosine aptamer sequence. In the presence of adenosine, the aptamer bound with adenosine and folded to the complex structure, which precluded the reporter part carrying AuNPs to combine with the random coiled detection part. Therefore, the lower the concentration of adenosine, the more AuNPs combined to the crystal. The resulting aptasensor showed a linear response to the increase of the adenosine concentration in the range of 0-2 μM with a linear correlation of r=0.99148 and a detection limit of 65 nM. Moreover, the aptasensor exhibited several excellent characteristics such as high sensitivity, selectivity, good stability, and reproducibility.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Sheng
authors.initials: S
authors.lastname: Cheng
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Michael Hon-Wah
authors.initials: MH
authors.lastname: Lam
authors.forename: Haojun
authors.initials: H
authors.lastname: Liang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold