Development of a Radio-frequency Biosensor with Amplified Gold Nanoparticles for Protein and DNA Detection

This study presents a novel detection method for protein and DNA with multi-layer AuNPs to enhance overall detection sensitivity. Since the electromagnetic behaviors of the sensors can be altered by utilizing the existence of multilayer AuNPs in the biosensor, the change of the bandwidth of the sensing circuits can be the critical factor in evaluating the performance of the proposed biosensor.
The measured 3-dB bandwidth of the original biosensor is about 18.8 GHz, which is close to the simulated results. The change in bandwidth for multi-layer AuNPs, which is formed by complementary target DNA, exceeds that of the double-layer AuNPs by 0.5 GHz. The changes of the 3-dB bandwidth are proportional to the logarithmic values of the analyte concentrations. Furthermore, the detection limit of the developed biosensor for the DNA set in this essay is 10pM, while it is 1ng/μL for the protein in this essay. In addition, with the temperature controlling system, single mutation of target DNA could be distinguished as the tested target DNA with an approximated length of 27 bps.
The experimental results in this study indicate that this biosensor and chemical detection methodology are successful. As health care becomes much more essential in modern life, this biosensor has potential applications in a screening kit for recognizing, sensing, and quantifying biomolecules in real samples.