Method and apparatus for detecting DNA hybridization

A biosensor cell for identifying an unknown DNA sample, said cell comprising:

• a first voltage divider circuit capable of generating a first reference voltage signal;
• a second voltage divider circuit capable of generating a second reference voltage signal;
• and
• a differential amplifier receiving said first reference voltage signal and said second reference voltage signal as input signals, and for generating an output signal, said output signal representing a difference between said first reference voltage signal and said second reference voltage signal;
• wherein said second voltage divider circuit includes a first floating gate transistor comprising a floating gate terminal having a known DNA sample disposed thereon and capable of receiving said unknown DNA sample, said first floating gate transistor having a conductance value which varies if hybridization occurs between said known DNA sample and said unknown DNA sample when said unknown DNA sample is delivered to said floating gate terminal of said first floating gate transistor.

A biosensor cell for identifying an unknown DNA sample, said cell comprising:

• means for generating a first reference voltage signal;
• means for generating a second reference voltage signal;
• and
• means for receiving said first reference voltage signal and said second reference voltage signal as input signals, and for generating an output signal, said output signal representing a difference between said first reference voltage signal and said second reference voltage signal;
• wherein said means for generating said first reference voltage includes a first floating gate transistor comprising a floating gate terminal having a known DNA sample disposed thereon and capable of receiving said unknown DNA sample, said first floating gate transistor having a conductance value which varies if hybridization occurs between said known DNA sample and said unknown DNA sample when said unknown DNA sample is delivered to said first floating gate terminal of said first floating gate transistor.

A method of identifying an unknown DNA sample, said method comprising the steps of:

• generating a first reference voltage signal;
• generating a second reference voltage signal utilizing a first floating gate transistor having a floating gate terminal, said floating gate terminal having a known DNA sample disposed thereon and capable of receiving said unknown DNA sample, said first floating gate transistor having a conductance value which varies if hybridization occurs between said known DNA sample and said unknown DNA sample when said unknown DNA sample is delivered to said floating gate terminal;
• and
• generating an output signal representing a difference between said first reference voltage signal and said second reference voltage signal.