Design Nanoprobe Based on Its Binding with Amino Acid Residues on Cell Surface and Its Application to Electrochemical Analysis of Cells.

Nanoprobe usually plays a vital role in the development of new electrochemical methods for cell analysis. However, nearly all of the currently used versatile probes are prepared by using lectin. So, a new kind of universal nanoprobe is designed and fabricated in this work for electrochemical cell analysis. Specifically, p-sulfonatocalix[4]arene-modified silver nanoparticles ( pSC4-AgNPs) are synthesized and explored as a universal nanoprobe. In this probe, pSC4 can recognize and bind to various amino acid residues on the membrane protein, and AgNPs can give a sensitive electrochemical signal. Therefore, by using the pSC4-AgNPs as a probe, a variety of cells can be well-detected, and the testing results are comparable, showing that the probe has good versatility. At the same time, the detection sensitivity reaches five cells, which is much better than other methods for electrochemical analysis of cells, showing its application prospect in trace cell analysis. In view of the advantages including simplicity of synthesis, stability of pSC4 moiety, and redox capability of AgNPs, the nanoprobe pSC4-AgNPs show a great potential in the development of electrochemical methods for cell detection.