TY - JOUR

T1 - Low-cost microfluidic sensors with smart hydrogel patterned arrays using electronic resistive channel sensing for readout

AU - Leu, Hsuan Yu

AU - Farhoudi, Navid

AU - Reiche, Christopher F.

AU - Körner, Julia

AU - Mohanty, Swomitra

AU - Solzbacher, Florian

AU - Magda, Jules

N1 - Funding information: Funding: We gratefully acknowledge research funding support from the University of Utah Research Foundation and the Joe W. and Dorothy Dorsett Brown Foundation as well as the Olive Tupper Foundation.

PY - 2018/12

Y1 - 2018/12

N2 - There is a strong commercial need for inexpensive point-of-use sensors for monitoring disease biomarkers or environmental contaminants in drinking water. Point-of-use sensors that employ smart polymer hydrogels as recognition elements can be tailored to detect almost any target analyte, but often suffer from long response times. Hence, we describe here a fabrication process that can be used to manufacture low-cost point-of-use hydrogel-based microfluidics sensors with short response times. In this process, mask-templated UV photopolymerization is used to produce arrays of smart hydrogel pillars inside sub-millimeter channels located upon microfluidics devices. When these pillars contact aqueous solutions containing a target analyte, they swell or shrink, thereby changing the resistance of the microfluidic channel to ionic current flow when a small bias voltage is applied to the system. Hence resistance measurements can be used to transduce hydrogel swelling changes into electrical signals. The only instrumentation required is a simple portable potentiostat that can be operated using a smartphone or a laptop, thus making the system suitable for point of use. Rapid hydrogel response rate is achieved by fabricating arrays of smart hydrogels that have large surface area-to-volume ratios.

AB - There is a strong commercial need for inexpensive point-of-use sensors for monitoring disease biomarkers or environmental contaminants in drinking water. Point-of-use sensors that employ smart polymer hydrogels as recognition elements can be tailored to detect almost any target analyte, but often suffer from long response times. Hence, we describe here a fabrication process that can be used to manufacture low-cost point-of-use hydrogel-based microfluidics sensors with short response times. In this process, mask-templated UV photopolymerization is used to produce arrays of smart hydrogel pillars inside sub-millimeter channels located upon microfluidics devices. When these pillars contact aqueous solutions containing a target analyte, they swell or shrink, thereby changing the resistance of the microfluidic channel to ionic current flow when a small bias voltage is applied to the system. Hence resistance measurements can be used to transduce hydrogel swelling changes into electrical signals. The only instrumentation required is a simple portable potentiostat that can be operated using a smartphone or a laptop, thus making the system suitable for point of use. Rapid hydrogel response rate is achieved by fabricating arrays of smart hydrogels that have large surface area-to-volume ratios.

KW - Fast response time

KW - Microfluidic sensors

KW - Smart hydrogels

KW - UV photopolymerization

UR - http://www.scopus.com/inward/record.url?scp=85074296121&partnerID=8YFLogxK

U2 - 10.3390/gels4040084

DO - 10.3390/gels4040084

M3 - Article

AN - SCOPUS:85074296121

VL - 4

JO - Gels

JF - Gels

IS - 4

M1 - 84

ER -