Author(s)

Ping Chen¹, Ruiying Zhang², Qifeng Jiang², Xingliang Xiong², Shixiong Deng^2*

¹Experimental Teaching Management Center, Chongqing Medical University, Chongqing, China.
²Laboratory of Biomedical Engineering, Chongqing Medical University, Chongqing, China.

In this report, we present a method for the detection of Pb²⁺ based on the different adsorption capacity on the surface of gold nanoparticles (AuNPs) between ssDNA (single-stranded DNA) and G-quartet. In the absence of Pb²⁺, the DNA oligonucleotides probe, which is guanine-rich ssDNA, can be adsorbed on the surface of AuNPs protecting them from aggregation. After adding Pb²⁺, the DNA oligonucleotides probe can specifically form compact G-quartet, which can induce the aggregation of unmodified AuNPs, especially after adding NaCl aqueous solution. Consequently, the color turns from red to blue. Pb²⁺ can be detected by colorimetric response of AuNPs; its detection limit can reach 5 μM only observed by naked eyes. Most metal ions have no interferences, and the interference of Cu²⁺ can be effectively eliminated by adding cysteine. It provides a simple and effective colorimetric sensor for on-site and real time detection of Pb²⁺.

Gold Nanoparticles, G-Quartet, Pb²⁺, Colorimetric Detection

Chen, P. , Zhang, R. , Jiang, Q. , Xiong, X. and Deng, S. (2015) Colorimetric Detection of Lead Ion Based on Gold Nanoparticles and Lead-Stabilized G-Quartet Formation. Journal of Biomedical Science and Engineering, 8, 451-457. doi: 10.4236/jbise.2015.87042.