Molecular Commonality Detection Using an Artificial Enzyme Membrane for in Situ One-Stop Biosurveillance

Abstract

Biodetection and biosensing have been developed based on the concept of sensitivity toward specific molecules. However, current demand may require more levelheaded or far-sighted methods, especially in the field of biological safety and security. In the fields of hygiene, public safety, and security including fighting bioterrorism, the detection of biological contaminants, e.g., microorganisms, spores, and viruses, is a constant challenge. However, there is as yet no sophisticated method of detecting such contaminants in situ without oversight. The authors focused their attention on diphosphoric acid anhydride, which is a structure common to all biological phosphoric substances. Interestingly, biological phosphoric substances are peculiar substances present in all living things and include many different substances, e.g., ATP, ADP, dNTP, pyrophosphate, and so forth, all of which have a diphosphoric acid anhydride structure. The authors took this common structure as the basis of their development of an artificial enzyme membrane with selectivity for the structure common to all biological phosphoric substances and studied the possibility of its application to in situ biosurveillance sensors. The artificial enzyme membrane-based amperometric biosensor developed by the authors can detect various biological phosphoric substances, because it has a comprehensive molecular selectivity for the structure of these biological phosphoric substances. This in situ detection method of the common diphosphoric acid anhydride structure brings a unique advantage to the fabrication of in situ biosurveillance sensors for monitoring biological contaminants, e.g., microorganism, spores, and viruses, without an oversight, even if they were transformed.

Artificial-enzyme gel membrane-based biosurveillance sensor with high reproducibility and long-term storage stability

“…The basic design of the artificial enzyme consisted of a metal coordinative polymer, copper ions, and counter polymer(s) with functional residues. 16 In the artificial-enzyme structure, numerous metal-coordinated nano-cavities were accumulated as the active site for catalytic activity. In previous study, the weak efficiency of membrane formation proved problematic for the design of an artificial enzyme, which had the characteristic of readily swelling in solution, which meant that it was too flexible to have good reproducibility.…”

“…Artificial enzymes are advantageous in that selectivity and stability can be designed. [15][16][17] We designed, synthesized, and evaluated an artificial-enzyme membrane, a type of polymer metal matrix for use as a sensor application. The metal complex cavity is a key component that ensures catalytic activity.…”

“…The metal complex cavity is a key component that ensures catalytic activity. 16 Many enzymes contain metal complexes as active centers or catalysis-related components of the protein structure. In our artificial-enzyme membrane, the Cu(II) complex is employed as the active center for the catalytic hydrolysis of the diphosphoric acid anhydride structure.…”

“…In our artificial-enzyme membrane, the Cu(II) complex is employed as the active center for the catalytic hydrolysis of the diphosphoric acid anhydride structure. 16 The membrane form also acts as a comprehensive molecular selection layer for biological phosphoric substances. This type of membrane can be used to fabricate a sensor device on an electrode or other type of transducer.…”

“…This type of membrane can be used to fabricate a sensor device on an electrode or other type of transducer. 16,17 Previously, we constructed an artificial-enzyme membrane that consisted of two different polymer chains and a coordinated metal ion. However, the efficacy of membrane formation was poor; its characteristic of swelling in solution was too flexible to have good reproducibility.…”