The innovation engine for new materials

Matthew Oshefsky

Matthew Oshefsky


University of California Santa Barbara


Chemical Engineering


Hamed Tavakoli

Faculty Sponsor(s): 

James Li

Faculty Sponsor's Department(s): 

Chemistry and Biochemistry

Project Title: 

Rapid detection of Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible Staphylococcus aureus (MSSA) using a low-cost thermometer

Project Description: 

The development of a rapid and inexpensive diagnosis test to detect and differentiate Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible Staphylococcus aureus (MSSA) is vital for lessening the health impact of antibiotic resistance. Herein, we used a thermometer to detect MRSA and MSSA microorganisms directly at the point of care by measuring the temperature differences caused by the photothermal aggregation of gold nanoparticles (AuNPs). The target MRSA and MSSA strains were specifically recognized by their corresponding ssDNA aptamers. This complexing of ssDNA aptamer to the target MRSA microorganism increased the aggregation of AuNPs, leading to a higher temperature increase. It was preliminarily determined that MRSA at 15 CFU/mL was reliably detected with a temperature change above 20 ℃ compared to the negative control. Various effective parameters including changing the NaCl concentration, ssDNA aptamer concentration, laser Irradiation time, Inbuation time, and Power Density were optimized. Also, sensitivity and specificity were evaluated under optimized conditions. This detection method can be applied as a point of care test (POCT) for the rapid detection of antibiotic-resistant strains of Staphylococcus aureus