A sensitive signal-off electrogenerated chemiluminescence biosensing method for the discrimination of DNA hydroxymethylation based on glycosylation modification and signal quenching from ferroceneboronic acid

作者：Zhang, Yuling; Li, Yan^*; Wei, Yingying; Sun, Huiping; Wang, Huan

来源：Talanta, 2017, 170: 546-551.

DOI：10.1016/j.talanta.2017.04.051

• Electrogenerated chemiluminescence
• 5-hydroxymethylcytosine
• T4 beta-glucosyltransferase
• Ferroceneboronic acid

In this study, a new and sensitive signal-off electrogenerated chemiluminescence (ECL) biosensing method for the quantification of 5-hydroxymethylcytosine in DNA (5-hmC-DNA) was developed. The method achieved simple and sensitive detection of 5-hmC-DNA based on the glycosylation of 5-hmC, combining both the amplification function of gold nanoparticles (AuNPs) and the high quenching efficiency of the tris(2, 2'ripyridine) dichlororuthenium(10 (Ru(bpy)(3)(2+)-ferrocene (Fc) system. First, the electrode modified with a mixture of Nafion and AuNPs was utilized as the platform for electrostatically adsorbing Ru(bpy)(3)(2+)(an ECLemitting species) and assembling 5-hmC-DNA. The 5-hmC-DNA was glycosylated by T4 beta-glucosyltransferase, yielding beta-glucosy1-5-hydroxymethyl-cytosine in DNA (5-ghmC-DNA). Finally, quencher-FcBA was further covalently bound to 5-ghmC-DNA through formation of boronate ester covalent bonds between boronic acid and cis-diols of 5-ghmC, resulting in a decrease in ECL intensity. The results indicated that the decreased ECL intensity was directly linear to the concentration of 5-hmC-DNA in the range from 1.0x 10(-8) to 5.0x10(-11) M with a low detection limit of 1.63 x 10-11 M. In addition, this ECL method was demonstrated to be useful for the quantification of 5-hmC in clinical serum samples. Moreover, the method allowed good discrimination among cytosine (5-C), 5-methylcytosine (5-mC), and 5-hmC in DNA.

• 出版日期2017-8-1
• 单位西北大学