Label-free protein and pathogen detection using the atomic force microscope.

The atomic force microscope (AFM) uses a sharp micron-scale tip to scan and amplify surface features, providing exceptionally detailed topographical information with magnification on the order of x10(6). This instrument is used extensively for quality control in the computer and semiconductor industries and is becoming a progressively more important tool in the biological sciences. Advantages of the AFM for biological application include the ability to obtain information in a direct, label-free manner and the ability to image in solution, providing real-time data acquisition under physiologically relevant conditions. A novel application of the AFM currently under development combines its surface profiling capabilities with fixed immuno-capture using antibodies immobilized in a nanoarray format. This provides a distinctive platform for direct, label-free detection and characterization of viral particles and other pathogens.