Lab-on-a-disc platform for screening of genetically modified E. coli cells via cell-free electrochemical detection of p-Coumaric acid

• Published in: Sensors and actuators. B, Chemical Vol. 253; pp. 999 - 1005
• Main Authors: Sanger, Kuldeep, Zór, Kinga, Bille Jendresen, Christian, Heiskanen, Arto, Amato, Letizia, Toftgaard Nielsen, Alex, Boisen, Anja
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-12-2017; Elsevier Science Ltd
• Subjects: Bacterial metabolite; Cell free detection; Cells; Chromatography; Correlation analysis; E coli; Electrochemical analysis; Electrochemical sensor; Electrode on plastic substrate; Electrodes; Filtration; Genetic modification; Genetically modified organisms; Lab-on-a-disc; Magnetic clamping; Metabolites; Pretreatment; Robustness; Screening; Sensors; Square waves; Substrates; Lab-on-a-disc; Magnetic clamping; Electrode on plastic substrate; Cell free detection; Electrochemical sensor; Bacterial metabolite
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.06.184

•Lab-on-a-disc device was developed for screening of genetically modified strains.•p-Coumaric acid was measured using electrodes fabricated on plastic substrate.•The centrifugal platform incorporates eight sample filtration and detection units.•The measured metabolite produced by E.coli correlates with data from HPLC analysis.
We present a robust easy to use lab-on-a-disc (LoD) device with integrated sample pre-treatment and electrochemical detection system for cell-free detection of a secondary metabolite, p-Coumaric acid (pHCA), produced by genetically modified E. coli. In the LoD device, which incorporates eight filtration and electrochemical detection units, the sample filtration was performed by rotating the disc using a programmable closed-loop stepper motor. The electrodes, patterned on plastic substrate, were connected through a printed circuit board to the slip ring using a robust magnetic clamping system that enables easy assembly and robust electrical connections. pHCA was quantified in a linear range from 0.125 up to 2mM using square wave voltammetry. The platform was successfully used for the quantification of pHCA produced by two genetically modified E. coli strains after 24h of cell culture. The data obtained from the electrochemical measurements showed good correlation with high performance liquid chromatographic analysis. The developed LoD system offers fast and easy detection of pHCA, enabling screening of genetically modified organisms based on the quantity of produced secondary metabolites.