Jiangsu University, China
Huanhuan Li has completed his master degree at the age of 25 years from Jiangsu University and pursue her PhD in Jiangsu University School of Food and Biological Engineering. He has published 8 SCI papers in reputed journals and has been published one paper in the journal of sub-nature (Scientific reports)
Rare earth-doped upconversion nanoparticles (UCNPs) possess peculiar frequency upconverting capabilities and high detection sensitivity qualities which present them as a potent alternative biosensor requisite for the detection of pathogenic bacteria. This paper reports a novel dual-color UCNP-based bacterium-sensing biosensor for Escherichia coli and Staphylococcus aureus detection simultaneously using UCNP as a fluorescence marker conjugated with antibodies as the specific molecular recognition unit. Dual-color UCNPs were fabricated via varying doped rare-earth ions to acquire the well-separated emission peaks. Dual-color UCNPs conjugated with antibody of E.coli and S.aureus for use as fluorescent probes. When E.coli and S.aureus were added into the reaction system, the fluorescent probes will capture the target bacteria through the specific binding of antibody, and then the fluorescence intensities decreased (∆I=Io-I) were observed to increase linearly with the concentration of the E.coli (664 nm) and S.aureus (806 nm) from 47 to 47×106 cfu mL-1 (y=199.45x-207.95, R2=0.98) and 64 to 64×106 cfu mL-1 (y=281.94x-116.19, R2=0.9657), respectively, resulting in the relatively low limit of 13 cfu mL-1 and 15 cfu mL-1 for E.coli and S.aureus, respectively. Furthermore, this UCNP-based bacterium-sensing biosensor was also could be successfully applied to simultaneous detect E.coli and S.aureus in adulterated meat and milk samples.