title: Biocompatible enzymatic roller pens for direct writing of biocatalytic materials: "do-it-yourself" electrochemical biosensors.
abstract: The development of enzymatic-ink-based roller pens for direct drawing of biocatalytic sensors, in general, and for realizing renewable glucose sensor strips, in particular, is described. The resulting enzymatic-ink pen allows facile fabrication of high-quality inexpensive electrochemical biosensors of any design by the user on a wide variety of surfaces having complex textures with minimal user training. Unlike prefabricated sensors, this approach empowers the end user with the ability of "on-demand" and "on-site" designing and fabricating of biocatalytic sensors to suit their specific requirement. The resulting devices are thus referred to as "do-it-yourself" sensors. The bio-active pens produce highly reproducible biocatalytic traces with minimal edge roughness. The composition of the new enzymatic inks has been optimized for ensuring good biocatalytic activity, electrical conductivity, biocompati-bility, reproducible writing, and surface adherence. The resulting inks are characterized using spectroscopic, viscometric, electrochemical, thermal and microscopic techniques. Applicability to renewable blood glucose testing, epidermal glucose monitoring, and on-leaf phenol detection are demonstrated in connection to glucose oxidase and tyrosinase-based carbon inks. The "do-it-yourself" renewable glucose sensor strips offer a "fresh," reproducible, low-cost biocatalytic sensor surface for each blood test. The ability to directly draw biocatalytic conducting traces even on unconventional surfaces opens up new avenues in various sensing applications in low-resource settings and holds great promise for diverse healthcare, environmental, and defense domains.
authors.affiliation: Department of NanoEngineering, University of California, San Diego La Jolla, CA, 92093, USA.
authors.forename: Amay J
authors.initials: AJ
authors.lastname: Bandodkar
authors.affiliation: Department of NanoEngineering, University of California, San Diego La Jolla, CA, 92093, USA.
authors.forename: Wenzhao
authors.initials: W
authors.lastname: Jia
authors.affiliation: Department of NanoEngineering, University of California, San Diego La Jolla, CA, 92093, USA.
authors.forename: Julian
authors.initials: J
authors.lastname: Ramírez
authors.affiliation: Department of NanoEngineering, University of California, San Diego La Jolla, CA, 92093, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D001672:Biocompatible Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D004553:Electric Conductivity; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000737:chemistry; D006801:Humans; D011092:Polyethylene Glycols / Q000737:chemistry; D014993:Xylitol / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D011092:Polyethylene Glycols; D002244:Carbon; D048271:Chitosan; D005949:Glucose Oxidase; D005947:Glucose; D014993:Xylitol
keywords: biosensors; diabetes; direct writing; electrodes; fabrication