NANOPARTICLES-BASED ELECTROCHEMICAL BIOSENSOR FOR SINGLE BACTERIUM DETECTION BY REDOX SIGNAL AMPLIFICATION

In this work, we report a portable microfluidic 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 electroactive molecules modified on Si-Porous-Pt MSNs(Mesoporous Silica Nanoparticles) to detect and differentiate Staphylococcus aureus and Pseudomonas aeruginosa. The detection limit of these two electroactive 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/μl) is detected by CV measurements. The liner detection limit concention is form 11000 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.