Abstract:

BACKGROUND: In electrochemical gene chip, chemical modification of the indium tin oxide (ITO) films carrier materials and DNA hybridization reactions need to carry on the different media solutions. The corrosion of various media would have a greater influence on characteristics of the carrier materials, and may be cause degradation or failure phenomenon of the carrier materials.
OBJECTIVE: To observe the electrical stability of the ITO films carrier materials in NaOH, NaCl, Na₂SO₄,  H₂SO₄  media solutions.
METHODS: The electrical stability of the ITO films carrier materials of electrochemical DNA biochip was investigated using the relative resistance change (ΔR/R) method in 1 mol/L NaOH, NaCl, Na₂SO₄, H₂SO₄ media solutions at 25 ℃ and 50 ℃.
RESULTS AND CONCLUSION: The ΔR/R values of ITO films showed the same change trends in four media solutions. With increasing the immersion time, the ΔR/R values of the films increased and the conductivity of the films decreased. However, with increasing medium solution temperatures, the electrical stability of the films decreased significantly, and the failure phenomenon of the electrical properties of the films occurred. The electrical stability of the ITO films in four media solutions decreased as NaOH, Na₂SO₄, NaCl and  H₂SO₄  solutions in sequence. The above-mentioned phenomenon was due to the different corrosion mechanism of the ITO films in media solutions.