Sub-attomolar electrochemical measurement of DNA hybridization based on the detection of high coverage biobarcode latex labels at PNA-modified screen printed electrodes.
We have constructed biobarcode labels based on 468nm diameter latex spheres. Modification with polyallylamine and then glutaraldehyde was used to attach a high DNA loading, consisting of aminated probe DNA (approx. 1.01×102molecules per sphere) and biobarcode DNA (approx. 1.66×104molecules per sphere). Detection of the biobarcodes was performed by application of a Ag enhancer solution, causing association of the Ag+ions with the phosphate groups of the DNA. The deposited Ag was detected by differential pulse voltammetry. A 30 mer sequence from the BL21 strain of E. coli was detected with an LOD of 2.6fM (calibration range 10 aM to 0.1pM, r2=0.91, n=45). The LOD was lowered to 0.56aM (calibration range 100zM to 0.1nM, r2=0.991, n=50) by utilizing a sandwich assay with PNA-modified screen printed electrodes, which lowered the Ag background current. The sandwich assay platform was used to calibrate E. coli strain BL2(DE3) with an LOD of 17.0 CFU mL-1(calibration range 10 to 106CFU mL-1, r2=0.99, n=33) with good discrimination against Salmonella.
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand; Faculty of Agriculture Technology, Brawijaya Univeristy, Malang, East Java 65145, Indonesia.
Tarina
T
Widaningrum
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand; Faculty of Agriculture Technology, Brawijaya Univeristy, Malang, East Java 65145, Indonesia.
Endrika
E
Widyastuti
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.
Feby Wijaya
FW
Pratiwi
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.
Ai Imas
AI
Faidoh Fatimah
Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at King Mongkut's University of Technology Thonburi (Bangkhuntien), Thailand.
Patsamon
P
Rijiravanich
Biochemical Engineering and Pilot Plant Research and Development Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at King Mongkut's University of Technology Thonburi (Bangkhuntien), Thailand. Electronic address: mithran.somasundrum@gmail.com.
Mithran
M
Somasundrum
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand; Nanoscience & Nanotechnology Graduate Program, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand. Electronic address: werasak@pdti.kmutt.ac.th.
Werasak
W
Surareungchai
D004269:DNA, Bacterial / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004926:Escherichia coli / Q000235:genetics; D007840:Latex / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D011327:Printing
D004269:DNA, Bacterial; D007840:Latex; D020135:Peptide Nucleic Acids
E. coli; Electrochemical; Nucleic acid; PNA; Voltammetry