A novel application of atomic force microscopy (AFM) in the rapid, label-free detection and identification of viruses is described. Multiplexed, miniaturized antibody domains were constructed using "ink-jet" protein arraying technology. The solid-phase affinity substrate termed the "ViriChip" was used in the immunocapture of bacteriophage fd, canine parvoviruses, and coxsackieviruses and analyzed by AFM. Immunocapture was found to be antibody-specific with a sensitivity of 10(8) pfu/ml in 30 min. Virus binding was found to be linear for concentration between 10(8) and 10(10) pfu/ml and did not reach saturation through 4 h. (C) 2003 Elsevier Inc. All rights reserved.