Application of hydrogel-coated microcantilevers as sensing elements for pH

Gonska, Julian; Schelling, Christoph; Urban, G.

doi:10.1088/0960-1317/19/12/127002

Cited by 13 publications

(7 citation statements)

References 27 publications

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“…Hydrogels are also used for a variety of sensing applications . Besides biosensors, we find, for example, ion, pH, oxygen, humidity, and ethanol vapor sensors. In biosensor applications, where surface-sensitive detection methods such as ellipsometry or surface plasmon resonance (SPR) are used, hydrogels act as surface-enlarging matrices into which ligands, ranging from small molecules to proteins and ultimately to cells, are immobilized, allowing the number of adsorbed ligands per surface area to be increased far beyond the equivalent of a monolayer.…”

Section: Introductionmentioning

confidence: 99%

Swelling of Thin Poly(ethylene glycol)-Containing Hydrogel Films in Water Vapor—A Neutron Reflectivity Study

Ederth

Ekblad

2018

Langmuir

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Hydrogels are widely used in biomedicine and for bioanalytical purposes, normally under wet conditions. For certain applications, processing steps, or process monitoring, hydrogel films are used or treated under ambient conditions, and because they are hygroscopic, it is of interest to investigate how they respond to changes in atmospheric humidity. We have used neutron reflectometry to follow the swelling of thin UV-polymerized hydrogel films in air under different relative humidities (RHs). These polymers were prepared to similar thicknesses on silica and gold substrates, and the chemical similarity between them was verified by infrared spectroscopy. The swelling in response to variations in RH was different for the layers on the two substrate types, reflecting structural changes induced by differences in the UV exposure required to achieve a given polymer thickness, as demonstrated also by differences in the Flory-Huggins interaction parameter, obtained by fitting a Flory-Huggins-type sorption model to the swelling data. Wetting studies show small changes in contact angles with surrounding humidity variations, indicating that structural reorganization at the interface in response to humidity changes is limited.

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Section: Introductionmentioning

confidence: 99%

Swelling of Thin Poly(ethylene glycol)-Containing Hydrogel Films in Water Vapor—A Neutron Reflectivity Study

Ederth

Ekblad

2018

Langmuir

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“…Different thin films of homopolymers and copolymers [87][88][89][90], amphiphilic block copolymers [91], polymer brushes [92], nanotubes [93] and nanoparticles [94] have been proposed as potential smart materials both for novel biomaterials development and for biosensing applications.…”

Section: Microcantileversmentioning

confidence: 99%

Microcantilevers and organic transistors: two promising classes of label-free biosensing devices which can be integrated in electronic circuits

et al. 2011

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Most of the success of electronic devices fabricated to actively interact with a biological environment relies on the proper choice of materials and efficient engineering of surfaces and interfaces. Organic materials have proved to be among the best candidates for this aim owing to many properties, such as the synthesis tunability, processing, softness and self-assembling ability, which allow them to form surfaces that are compatible with biological tissues. This review reports some research results obtained in the development of devices which exploit organic materials' properties in order to detect biologically significant molecules as well as to trigger/capture signals from the biological environment. Among the many investigated sensing devices, organic field-effect transistors (OFETs), organic electrochemical transistors (OECTs) and microcantilevers (MCLs) have been chosen. The main factors motivating this choice are their label-free detection approach, which is particularly important when addressing complex biological processes, as well as the possibility to integrate them in an electronic circuit. Particular attention is paid to the design and realization of biocompatible surfaces which can be employed in the recognition of pertinent molecules as well as to the research of new materials, both natural and inspired by nature, as a first approach to environmentally friendly electronics.

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“…The precision could be enhanced by increasing the X-ray magnification and using antiscatter grids to increase image contrast, using computational image analysis to more precisely quantify marker position, increasing hydrogel length, changing the hydrogel composition to a material with a sharper pH transition, [105,106] or amplifying the small change in expansion (e.g., using a multi-layer hydrogel as is done on cantilever-based sensors). [107][108][109]…”

Section: Limitationsmentioning

confidence: 99%

X‐Ray Visualized Sensors for Peritoneal Dialysis Catheter Infection

Kiridena

Wijayaratna

Levon

et al. 2023

Adv Funct Materials

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Peritonitis is a common complication for patients with end-stage renal disease undergoing peritoneal dialysis (PD) and is a direct cause or contributor in >15% deaths in PD patients. Since early detection is key to treatment, patients and their care teams need rapid, on-site diagnostics. A hydrogelbased peritoneal fluid pH sensor attached to a peritoneal dialysis catheter is developed to measure local acidosis indicative of peritoneal infections for early detection and monitoring of infections using X-ray imaging. The sensor comprises a polyacrylic acid hydrogel with embedded radiopaque markers enclosed in a polymer casing; contraction of the hydrogel in response to acidic pH is evident from the radiographically measured marker position. The sensor has a pH 4-8 response range; between pH 6.5 and 7.5 it responds linearly with a slope of 14% pH 7 length per pH unit, and about 1% length precision. The sensor is attached to a catheter and implanted in a rat peritoneum. Results in awake rats show a rapid pH drop during infection not observed in systemic C-reactive proteins (CRP) levels nor in the uninfected control animal, with negligible drift over 2 weeks. To our knowledge, this is the first report of an in vivo chemically responsive hydrogel sensor.

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Application of hydrogel-coated microcantilevers as sensing elements for pH

Cited by 13 publications

References 27 publications

Swelling of Thin Poly(ethylene glycol)-Containing Hydrogel Films in Water Vapor—A Neutron Reflectivity Study

Swelling of Thin Poly(ethylene glycol)-Containing Hydrogel Films in Water Vapor—A Neutron Reflectivity Study

Microcantilevers and organic transistors: two promising classes of label-free biosensing devices which can be integrated in electronic circuits

X‐Ray Visualized Sensors for Peritoneal Dialysis Catheter Infection

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