Functionalization of PVC membrane with ss oligonucleotides for a potentiometric biosensor

Area of Science:

• Analytical Chemistry
• Materials Science
• Biotechnology

Background:

• Polymeric membranes are crucial in ion-selective electrodes (ISEs).
• Single-stranded oligonucleotides (ssDNA) offer specific molecular recognition capabilities.
• Integrating ssDNA into ISE membranes presents opportunities for novel biosensors.

Purpose of the Study:

• To describe a novel application of ssDNA as an active component in a polymeric membrane for an ISE.
• To investigate different immobilization strategies for ssDNA probes on poly(vinyl chloride) (PVC) membranes.
• To evaluate the potentiometric detection of oligonucleotide hybridization using these modified membranes.

Main Methods:

• Immobilization of modified oligo(dA)(15) (cholesterol, triphenylmethyl, hexadecyl derivatives) into PVC membranes via extraction.
• Adsorption of unmodified oligo(dA)(15) onto PVC membranes using tridodecylmethyammonium chloride (TDDMA(+)Cl(-)).
• Potentiometric detection of hybridization between complementary oligonucleotides using modified ISEs.

Main Results:

• Immobilization of ssDNA probes via a spacer was more effective for potentiometric detection.
• Cholesterol-modified oligo(dA)(15) membranes showed sensitivity to complementary oligo(dT)(15) in the 2-80 nM range at pH 7.
• The study proposes a mechanism for the potentiometric detection of hybridization.

Conclusions:

• Single-stranded oligonucleotides can be successfully integrated into polymeric membranes for ISE applications.
• The developed ssDNA-modified ISEs demonstrate potential for sensitive and specific detection of oligonucleotide hybridization.
• This work opens avenues for developing advanced DNA-based electrochemical biosensors.