Nanoparticles-based electrochemical biosensor for single bacterium detection by redox signal amplification

In this work, we report a portable mierofluidie chip based on Si-Porous-Pt MSNs(Mesoporous Silica Nanoparticles) -enhanced electrochemical detection for single-bacteria diognostic. The possibility of single-bacteria detection is realized here by using electroactivc molecules modified on Si-Porous-Pt MSNs(Mcsoporous Silica Nanoparticles) to detect and differentiate Staphylococcus aureus and Pseudomonas aeruginosa. The detection limit of these two electroactivc molecules is near femtomolar (1 pM) when immobilized on Si-Porous-Pt MSNs(Mesoporous Silica Nanoparticles), and the minima amounts of gold NPs required in the detection is around thousands (103 particle/μl). A concentration of couples whole bacteria (<10 cells/μ1) is detected by CV measurements. The liner detection limit conccntion is form 1- 1000 cells/μl. The results showed that the portable biochip system has great potential as a device for single -particle or possibly even single-organism detection.