© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

4.2.4 Chemical Assay

It may also be useful to design a sensor that is capable of detecting as many different chemical species as possible, in contrast to detecting the precise concentration of a single species, for use in chemomessaging (Section 7.4.2.4), chemonavigation (Section 8.4.3), cellular diagnosis (Chapter 21), and other in vivo assay work. Counting rotors may be used for this purpose. Each 12-receptor sorting rotor/counting rotor pair has a minimum 400 nm³ volume.¹⁰ Allowing an additional ~800 nm³ per pair to account for power, control, mechanical attachments and housings, which includes ~300 nm³ per pair for sample chamber volume and sample access, requires ~100 nm³ per receptor, roughly the same as for the steric probe units described in Section 4.2.1. A dedicated 1 micron³ chemical assay nanorobot, which includes ~0.25 micron³ sample volume, with ~10⁷ pairs (receptors) could thus continuously scan for as many as ~10⁷ different chemical species, counting 'N ~ 1 large molecule/sec at concentrations of c_ligand ~ 10^-10 molecules/nm³.

Last updated on 17 February 2003