title: Aptamer-based colorimetric detection of platelet-derived growth factor using unmodified gold nanoparticles.
abstract: We developed a simple method for the detection of platelet-derived growth factors (PDGFs) based on base stacking effect coupled with an unmodified gold nanoparticle (AuNP) indicator. In the absence of a target, an aptamer probe and a capture probe stably co-exist in a solution, as it is difficult to sustain an interaction between both these probes due to the short 8bp duplex. However, when a target protein binds to the aptamer probe, the strong base stacking effect can lead to a favorable and stable interaction between the aptamer and capture probes. Hence, the capture probe dissociates from the AuNP surfaces, inducing AuNP aggregation. Compared with other AuNP-based aptasensors for PDGFs, using this base stacking effect can overcome a structured-aptamer method's limitation of requiring thiolated-aptamer-modified AuNPs. Under optimal detection conditions, this label-free colorimetric sensor could detect PDGFs down to 6nM with high selectivity in the presence of other interferring proteins. This simple detection approach provides viable methods for a structured-aptamer sensing protocol.
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Shih-Chung
authors.initials: SC
authors.lastname: Wei
authors.forename: Tzu-Heng
authors.initials: TH
authors.lastname: Wu
authors.forename: Chung-Han
authors.initials: CH
authors.lastname: Lee
authors.forename: Chii-Wann
authors.initials: CW
authors.lastname: Lin
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D010982:Platelet-Derived Growth Factor / Q000302:isolation & purification*; D011485:Protein Binding
chemical_list: D052157:Aptamers, Nucleotide; D010982:Platelet-Derived Growth Factor; D006046:Gold