A typical biosensor as shown in the figure below1 contains three main elements: a bioreceptor, a transducer, and a signal-processing element. The bioreceptor is sensitive to a particular analyte of target molecule of interest. The transducer detects that the bioreceptor has changed due to an interaction with the analyte. The signal processing elements buffers, amplifies or filters the detected signal.



There are two very good papers on biosensors in the IEEE Transactions on Nanotechnology.

• Real-Time, Label-Free Detection of Biological Entities Using Nanowire-Based FETs, by Curreli, M. Rui Zhang Ishikawa, F.N. Hsiao-Kang Chang Cote, R.J. Chongwu Zhou Thompson, M.E. Dept. of Chem., Univ. of Southern California, Los Angeles, CA
  • The biosensors in this paper are based on FET transducers, and many linker molecules and bioreceptors are described.
• Chemical Sensors and Electronic Noses Based on 1-D Metal Oxide Nanostructures by Po-Chiang Chen Guozhen Shen Chongwu Zhou Ming-Hsieh Dept. of Electr. Eng., Univ. of Southern California, Los Angeles, CA
  • The biosensors in this paper are primarily chemoresistors for gas sensing using many different metal oxide nanostructures.