Oligonucleotide-arrayed TFT photosensor applicable for DNA chip technology.

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Diagnostics

Background:

• DNA chip technology requires sensitive and specific detection methods.
• Thin film transistor (TFT) photosensors offer potential for miniaturized optical detection.
• Integrating TFTs with biosensing elements is crucial for advanced diagnostics.

Purpose of the Study:

• To develop and optimize a TFT photosensor for DNA chip applications.
• To evaluate the performance of the TFT photosensor for oligonucleotide immobilization and detection.
• To demonstrate the capability of the TFT photosensor in detecting single nucleotide polymorphisms (SNPs).

Main Methods:

• Fabrication of a TFT photosensor using semiconductor integrated circuit (IC) technology.
• Coating the TFT photosensor surface with titanium dioxide (TiO2) for optical filter fabrication.
• Optimizing the immobilization of thiolated oligonucleotide probes using APTES and GMBS.
• Utilizing quantum dots and Alexa Fluor 350 for detection.
• Examining single nucleotide polymorphism (SNP) detection using an oligonucleotide-arrayed TFT photosensor targeting the ALDH2 gene.

Main Results:

• Oligonucleotide coverage reached a plateau of 33.7 pmol/cm2.
• Lowest detection limits achieved were 0.05 pmol/cm2 (quantum dot) and 2.1 pmol/cm2 (Alexa Fluor 350).
• Successful detection of SNPs in ALDH2*1 and ALDH2*2 target DNA was demonstrated.
• DNA hybridization was observed using the oligonucleotide-arrayed TFT photosensor.

Conclusions:

• The developed TFT photosensor is suitable for DNA chip technology.
• The sensor demonstrates high sensitivity and specificity for oligonucleotide detection and SNP analysis.
• This technology enables the development of disposable photodetecting devices for genetic analysis.