Using the Ring-shaped Interdigitated Electrode Operated under AC Condition to Quantify Bacteria Number existing in Bio-related Samples

Abstract

According to the research of aquaculture industry As the total number of bacteria exceeds 1x105 CFU/mL in pound It would cause the grouper to be sick or dead even if cause a billion of dollars losses every year in industry Due to the conventional plate count method that has the complicated and time-consuming operation problem we cannot detect the sample immediately In this study the device is developed to detect the number of bacteria in aqueous solution within 15 min by following three stages (1) The stock solution of the sample should take pretreatment by centrifugal method and adjust the stock solution to 0 3 M sucrose solution (2) Then it could be dropped on the test platform of Ring-shaped Interdigitated Electrode (RIDE) of Lithography Instrument and Process to apply on the microelectromechanical microchip When adding the AC signal (40 Vpp 5 kHz) on electrode it would generate the continuity AC electroosmosis (ACEO) to drive the hydrated ion in aqueous solution to guide the bacterial into the electrode center it’s beneficial to image capture (3) In final ImageJ software was utilized for quantitative analysis In this research the application field has changed from aquaculture media in laboratory to real sample in fishery Recently results shows that we could quantify in 5 minutes Moreover we improved quantitative analysis by pretreatment chip design experimental methods and image-analyzing From result with 100 ?L volume sample RIDE system can detect concentration from 1x103 to 1x105 CFU/mL that has a positive linear correlation with cultivation-dependent methods It shows that the system is able to apply in fishery for quantitative detection of number of bacterial With well assembly and improved automation in this system the detecting time could be shortened to 10 minutes Comparing to the same range concentration for aquaculture media with vibrio count the attrition rate is just 10% Besides the fishery it will be possible to instantly detect bacteria counting such as bacteriuria food or environment for bacteria count in the future through this technology development

Date of Award	2015 Aug 26
Original language	English
Supervisor	Hsien-Chang Chang (Supervisor)