Lab on a chip sensor for rapid detection and antibiotic resistance determination of Staphylococcus aureus

Abstract

The Gram-positive bacterium, Staphylococcus aureus (S. aureus), is a major pathogen responsible for a variety of infectious diseases ranging from cellulitis to more serious conditions such as septic arthritis and septicaemia. Timely treatment with appropriate antibiotic therapy is essential to ensure clinical defervescence and to prevent further complications such as infective endocarditis or organ impairment due to septic shock. To date, initial antibiotic choice is empirical, using a "best guess" of likely organism and sensitivity- an approach adopted due to the lack of rapid identification methods for bacteria. Current culture based methods take up to 5 days to identify the causative bacterial pathogen and its antibiotic sensitivity. This paper provides proof of concept for a biosensor, based on interdigitated electrodes, to detect the presence of S. aureus and ascertain its sensitivity to flucloxacillin rapidly (within 2 hours) in a cost effective manner. The proposed method is label-free and uses non-faradic measurements. This is the first study to successfully employ interdigitated electrodes for the rapid detection of antibiotic resistance. The method described has important potential outcomes of faster definitive antibiotic treatment and more rapid clinical response to treatment.

Self-Organized Nanostructure Modified Microelectrode for Sensitive Electrochemical Glutamate Detection in Stem Cells-Derived Brain Organoids

“…We chose to test our microelectrode in a 3D organoid model in recognition of two-dimensional cell culture systems not being able to recapitulate the complexity of brain architecture and functioning. By creating nanostructures on the probe surface area we increased the binding capacity for the functional molecules to contribute in reactions at the surface, thus facilitating the acquisition and transportation of signals and improving sensitivity [ 24 , 25 , 26 , 27 , 28 ]. The performance of our nanotextured electrode was examined in hESC-derived organoids consisting of different neuronal populations that are representative of different brain regions and therefore likely differ in their glutamate levels.…”

A Label-Free, Quantitative Fecal Hemoglobin Detection Platform for Colorectal Cancer Screening

“…At 0.01 mg·Hb/g, 4 mg/g and 40 mg/g, the average difference compared with control samples is 2 mV, 3.19 mV and 6.27 mV. The non-zero change in voltage in the control sample, when PBS was added to functionalized surface could be attributed to the effect of Helmholtz double layer at lower frequencies [38] while for samples with hemoglobin, the voltage changes are primarily due to the binding of the hemoglobin protein to receptor antibody tethered to the sensor surface. The increased change in voltage with hemoglobin concentrations indicates that the impedance of the biosensor increases with the higher concentrations of hemoglobin.…”

“…In detail, the glass slide with IDE sensors was immersed in 2% APTES in 95% ethanol for 1 h to allow for the aqueous silanization of the oxide surface to occur. This aqueous silanization process has been extensively described elsewhere [36] and has been implemented for various sensing applications [37,38]. The slide was then washed thoroughly 3 times in ethanol (5 min each) before it was incubated in 2.5% glutaraldehyde in milli-Q water for 2 h. This created aldehyde groups (–COH) on the sensor surface.…”

Interdigitated and Wave-Shaped Electrode-Based Capacitance Sensor for Monitoring Antibiotic Effects

“…Staphylococcus aureus ( S. aureus ) is one of the pathogenic bacteria, which promotes infections by producing virulence factors and causes bacteremia, endocarditis, skin and soft tissue infections, as well as hospital-acquired infections. Under a long-term antibiotic treatment, the bacteria could develop resistance for certain antibiotics [ 3 , 4 ]. The engineered S. aureus such as methicillin-resistant S. aureus (MRSA) are antibiotic-resistant strains and resistive to a diverse spectrum of antibiotics [ 5 , 6 ].…”