DNA Extraction Principle Inspired Instantaneous Synthesis of DNA–Gold Nanoparticle Conjugates as Sensing Probes

Herein, we report a simple and rapid method for the synthesis of DNA–gold nanoparticle conjugates (DNA-AuNPs) relying on the mechanism of DNA extraction. By the addition of ethanol and NaCl to the mixture of DNA and AuNPs, charge-neutralized DNA strands are instantaneously decorated on AuNPs to form DNA-AuNPs. Meanwhile, the as-formed DNA-AuNPs are promptly salted and aggregated to facilitate subsequent rapid separation. The whole process requires no special reagents or instruments and can be easily completed in a few minutes. The prepared DNA-AuNPs exhibit high stability and are hybridizable. The proposed method simultaneously satisfies the demands of simplicity, rapidity, high DNA grafting density, scalability, and generality. This study provides an advanced strategy for the efficient synthesis of DNA-AuNPs for subsequent applications.