New immobilisation method for oligonucleotides on electrodes enables highly-sensitive, electrochemical label-free gene sensing

作者：Aydemir Nihan; Chan Eddie; Baek Paul; Barker David; Williams David E; Travas Sejdic Jadranka^*

来源：Biosensors and Bioelectronics, 2017, 97: 128-135.

DOI：10.1016/j.bios.2017.05.049

• Biomolecule immobilisation
• Label-free sensing
• Conducting polymers
• Electrochemical biosensors

We present a versatile and facile procedure for the immobilisation of bioprobe molecules to an electrochemical sensing element. We eliminate lengthy preparation procedures for direct functionalisation of electrode surfaces by pre-attaching probe molecules to carboxylic acid bearing termonomers of pyrrole phenylenes or thiophene phenylenes. We demonstrate that these conjugates can be electrodeposited at low potentials to form nano-scale porous, electroactive conducting polymer films, exposing the bioprobe and retaining activity and specificity for binding, exemplified here with DNA sensors. The electrochemical reaction impedance for Fe(CN)(6)(3-/4-) on oligonucleotide-modified electrodes showed remarkable (down to aM) detection sensitivity for target DNA sequences present in solution. Cross-sensitivity to non-complementary target sequences is small and multi target arrays are easily made. There is no need for labelling of either probe or target oligonucleotide.

• 出版日期2017-11-15