[Study of pH measuring based on i-motif DNA conformation switch and UV-Vis absorption spectroscopy of gold nanoparticles].
A fast, sensitive, colorimetric method for the detection of pH based on the differentiate effect of gold nanoparticles to the configuration of DNA was developed in this study. The UV-Vis absorption spectroscopy of the i-motif DNA-Au NPs system has been investigated, and the effect of the concentration of salt and i-motif DNA, reaction time and DNA sequence on the pH response of the system have been also optimized. Under the optimum conditions, the UV-Vis absorption spectroscopy of the Au NPs is changed regularly with pH in the range of 5.3 - 7.0, the absorbance at 520 nm is increased gradually while at 700 nm decreased. Correspondingly, the color of the Au NPs is varied from violet to red. The pH sensor is no need to modification, low cost, fast and can be carried out by naked eyes. It is promising to use in monitoring some life process which associated with pH variation.
Longyan Entry-Exit Inspection and Quarantine Bureau, Longyan 364000, China. zhongjianhai@yahoo.com.cn
Jian-hai
JH
Zhong
Liang-qia
LQ
Guo
Jin-mei
JM
Wu
Jin-feng
JF
Chen
Zhang-jie
ZJ
Chen
D003124:Colorimetry; D004247:DNA / Q000737:chemistry*; D006046:Gold; D053768:Metal Nanoparticles; D009690:Nucleic Acid Conformation; D013056:Spectrophotometry, Ultraviolet
D006046:Gold; D004247:DNA