Growth of Escherichia coli on the GaAs (001) surface

Abstract

Detection of pathogenic bacteria and monitoring their susceptibility to antibiotics are of great importance in the fields of medicine, pharmaceutical research, as well as water and food industries. In order to develop a photonic biosensor for detection of bacteria by taking advantage of photoluminescence (PL) of GaAs-based devices, we have investigated the capture and growth of Escherichia coli K12 on bare and biofunctionalized surfaces of GaAs (001) - a material of interest for capping different semiconductor microstructures. The results were compared with the capture and growth of Escherichia coli K12 on Au surfaces that have commonly been applied for studying a variety of biological and biochemical reactions. We found that neither GaAs nor Au-coated glass wafers placed in Petri dishes inoculated with bacteria inhibited bacterial growth in nutrient agar, regardless of the wafers being bare or biofunctionalized. However, the capture and growth of bacteria on biofunctionalized surfaces of GaAs and Au wafers kept in a flow cell and exposed to different concentrations of bacteria and growth medium revealed that the initial surface coverage and the subsequent bacterial growth were dependent on the biofunctionalization architecture, with antibody-coated surfaces clearly being most efficient in capturing bacteria and offering better conditions for growth of bacteria. We have observed that, as long as the GaAs wafers were exposed to bacterial suspensions at concentrations of at least 10 CFU/mL, bacteria could grow on the surface of wafers, regardless of the type of biofunctionalization architecture used to capture the bacteria. These results provide important insight towards the successful development of GaAs-based devices designed for photonic monitoring of bacterial reactions to different biochemical environments.

Sodium dodecyl sulfate decorated Legionella pneumophila for enhanced detection with a GaAs/AlGaAs nanoheterostructure biosensor

“…The quantum semiconductor photonic biosensing (QSPB) reader employed in this work used a 660 nm light emitting diode (LED) for the intermittent excitation of GaAs/AlGaAs biochips (3 s in every 60 s period) at P =25 mW/cm 2 . The specificity of the employed biosensing procedure has already been established in our previous publications [10,[25][26][27] and further illustrated in [11,[28][29][30].…”

Binding strategies for capturing and growing Escherichia coli on surfaces of biosensing devices

“…Previously, we observed that the growth of E. coli on GaAs or Au surfaces required a minimum of 10 5 CFU/mL [44], while testing the sensitivity of E. coli strains to antibiotics with a photoluminescence-based biosensor was not possible for bacterial concentrations under 2 x 10 8 CFU/mL [24]. It has been suggested that the toxic effects of to Ab that neutralize viruses versus Ab that react with viruses but do not neutralize them [45].…”

Biofunctionalisation of Gallium Arsenide with Neutravidin

“…For example, this platform can be used for the immobilisation of biotinylated antibodies or an enzyme or target protein conjugated to biotin . 3,19 Being composed of a dual-component monolayer, this system provides flexibility for customizing the density of binding sites on the surface.…”