Applications of Photoswitchable Biomaterials

1) Photoswitchable activation of enzymes provides a means to trigger a biocata-lytic transformation ON and OFF . This feature shows two important functions  

2) The concept of photoswitchable biomaterial can be extended to different biological functions, such as cofactors, inhibitors, enzymes, receptors, hormones, antigens/antibodies, DNA, etc. This opens a broad spectrum of applications in different biomaterial science disciplines. 

Photonic activation of redox enzymes results in the light-induced bioelectrocataly-tic activation of an enzyme cascade. This permits application of photoswitchable enzymes as amplifiers of weak photonic signals. Alternatively, sensitive actino-meters, measuring low irradiation doses, might be envisaged. 

Redox enzymes are the active component in many electrochemical enzyme electrode biosensor devices.1821 The integration of two different redox enzymes with an electrode support, in which one of the biocatalysts is photoswitchable between ON and OFF states, can establish a composite multisensor array. The biomaterial interface that includes the photoswitchable enzyme in the OFF state electrochemi-cally transduces the sensing event of the substrate corresponding to the nonphoto-switchable enzyme. Photochemical activation of the light-active enzyme leads to the full electrochemical response, corresponding to the analysis of the substrates of the two enzymes. As a result, the processing of the signals transduced by the composite biomaterial interface in the presence of the two substrates permits the assay of the 

Photoswitchable Biomaterial Area of Application System Configuration 

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Table 2 summarizes different possible applications of photoswitchable biomaterials, while detailing the nature of the biomaterial, the area of application, and, when possible, specific examples. Reversible light-induced activation and deactivation of redox proteins (enzymes) corresponds to write - read - erase functions. The photonic activation of the biomaterial corresponds to the write function, whereas the amperometric transduction of the recorded optical information represents the read function of the systems. Switching off of the redox functions of the proteins erases the stored photonic information and regenerates the photosensory biomaterial. These integrated, photoswitchable redox enzyme electrode assemblies mimic logic functions of computers, and may be considered as first step into the era of biocomputers. 

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