A label-free fluorescent biosensor for the detection of protein kinase activity based on gold nanoclusters/graphene oxide hybrid materials

作者：Liu, Qing; Li, Ning; Wang, Mengke; Wang, Lei; Su, Xingguang^*

来源：Analytica Chimica Acta, 2018, 1013: 71-78.

DOI：10.1016/j.aca.2018.01.053

• MUA-Au NCs
• Graphene oxide
• Fluorescence
• Protein kinase activity

Protein kinase (PKA) can regulate many cellular biological processes by phosphorylation substrate peptide or protein. A new fluorescent biosensing method for the detection of PKA activity was developed by using 11-mercaptoundecanoic acid-capped gold nanoclusters (MUA-Au NCs) and graphene oxide (GO) with low background noise. In this strategy, the special designed peptide could be anchored on the surface of MUA-Au NCs by the Au-S bond and also adsorbed on the surface of GO owing to the electrostatic interaction. As a result, the fluorescence of MUA-Au NCs was quenched leading to low background fluorescence due to the forster resonance energy transfer (FRET) between MUA-Au NCs and GO via peptide as a bridge. However, when the substrate peptide was phosphorylated by PKA, the FRET between GO and MUA-Au NCs was disrupted because of the weakened interaction between the phosphorylated peptide and the GO, resulting in recovery of the fluorescence intensity. The developed label-free fluorescence "turn-off-on" method can detect protein kinase activity in the range of 0.6-2.0 U mL(-1) with a detection limit of 0.17 U mL(-1) (3 sigma). The feasibility of this present method for kinase inhibitor screening was also studied by assessment of H-89 kinase inhibition with an IC50 value of 0.049 mu mol L-1.

• 出版日期2018-7-12
• 单位吉林大学