Sterilization of Escherichia coli O157:H7 using micro corona ionizer

Abstract

We demonstrated in vitro sterilization of Escherichia coli O157:H7 bacteria on agar by a pin-between-planes micro corona ionizer. The gap between the pin and the grid was ~1.1 mm, the length of the grid was ~2.1 mm and the height was ~1.0 mm. The effective pin radius and discharge length were both approximated to be 200 μm. Ozone generation rates of ~2.3 × 10(-3) mg/s, ~2.7 × 10(-3) mg/s and ~3.5 × 10(-3) mg/s at 1,500 V were calculated for relative humidity (RH) of 35 %, 25 % and 10 % respectively. Analytical ozone generation rate increases as RH decreases and it is consistent with experimental observations. Using target and control petri dishes with E. coli plated agar, the sterilization capability of the micro corona ionizer at 37 °C for 24 h was evaluated. A ~60 % reduction in bacterial colony was shown with plate counting and its kill radius could be tuned from ~ 20 mm to ~5 mm by reducing the duty cycle from 100 % to 50 % with 30 min pulse width. The results suggested that the micro corona ionizer might be suitable as a tunable ozone source in wound dressing for chronic wound management.

Miniaturized corona flow sensor operating in drift mobility increment mode for low flow velocity measurement

“…However, they can be used to evaluate the corona current versus drift mobility trend for pin-to-plane electrodes arrangement. In order to estimate the values for L and r o , we employed the approach by Chua and Son [35] which involved fitting the experimental I-V curves over the analytical equivalent as given by Eqs. (1a) and (1b).…”

“…Inspired by Wright and Gianchandani's DC plasma based gas pressure sensor [23], we have recently demonstrated air pressure sensing via a miniaturized corona device [24]. Note that miniaturized corona devices have also been previously explored for various applications that include ionization of air [25], air quality monitoring [26,27], air filtration [28,29], mechanical excitation of microfabricated structures [30][31][32][33], electronic cooling [34] and bacterial sterilization [35]. One of the key advantages of corona discharge over other types of electrical discharges is its low operating current.…”

Sterilization by Cooling in Isochoric Conditions: The Case of Escherichia coli

“…A sterilization phenomenon is also investigated with a pulsed electric field method, which generates pores in the membrane and organelles. Both techniques have not shown a relationship between the damage observed and microbial inactivation [ 1 , 4 – 7 ].…”