Electronic concentration of negatively-charged molecules on a microfabricated biochip

Various conditions leading to successful electronic concentration of negatively-charged molecules, notably oligonucleotides, on a microfabricated biochip have been studied. Tests on two chip designs have been performed. In the first generation biochip, which consisted of 12 electrodes 5 mm apart, fluorescent molecules were attracted to a positively-biased electrode leading to electronic concentration. In the second generation biochip, which consisted of eight electrodes 250 μm apart, much faster concentration rates were observed due to reduction in electrode spacing. These results are significant to design a pathogen detection biochip based on DNA hybridization assisted by electronic concentration.