Biosniffers (Gas‐Phase Biosensors) as Artificial Olfaction

Abstract

Biochemical gas sensors (called biosniffers have been developed as one of the gas‐phase bioassay approaches by using biological recognition systems such as drug metabolizing enzymes. Various kinds of volatile chemicals are analyzed by the biosniffers, with excellent gas selectivity being attributable to biological interactions such as enzyme specificity. The biochemical sniffers have been used for environmental assessment and human odor analysis as physiological and dental diagnoses. Potential application of the biosniffers includes not only its use, instead of sniffer dogs, in the detection of illegal drugs, nerve gases, and disaster victims but also artificial olfaction for smell informatics (smell communication, biometrics, etc.).

Analyte induced water adsorbability in gas phase biosensors: the influence of ethinylestradiol on the water binding protein capacity

“…At high concentrations of ETED in the gas phase, ETED induced structural reorganization of a large community of antibodies limited by steric conditions in a monomolecular layer of IgGs immobilized through protein A. According to previous work, 7,8 the biologically inspired protein A based self-assembling procedure leads to closepacked layers. As a result, ETED induced IgG transformations may cause only limited conformational rearrangements of immunoglobulin, opening access to only part of the "extra" hydrophilic regions of the protein globules, leading to "excessive" sorption of water molecules.…”

“…For measurements of ETED powders, the same QCM based electronic nose instrument was used with transducers modified with thermally evaporated thin films (100 nm) of annulenes (dibenzotetraazaannylene, H 2 TAA and tetramethyldibenzotetraazaannulene, H 2 TMTAA), calixarenes (tert-butylcalyx [4,6,8]arenes) and polyacenes (tetracene and pentacene), as well as metal free phtalocyanine H 2 Pc. 41…”

“…6,7 To date there has been a limited amount of work reported on gas phase biosensors (GPB, "biosniffers") where biomolecules are utilized for the detection of specific air-borne analytes. [8][9][10][11][12][13][14] Antibodies were initiated to use as sensing agent for QCM based GPB by the Guilbault group. [15][16][17][18] As an example, he reported the use of biomolecules on Quartz Crystal Microbalance (QCM) devices for vapor phase detection of formaldehyde and organophosphorous pesticides such as parathion.…”