Melnik Eva, Kurzhals Steffen, Mutinati Giorgio C, Beni Valerio, Hainberger Rainer
Molecular Diagnostics, AIT Austrian Institute of Technology GmbH, 1210 Vienna, Austria.
Bioelectronics and Organic Electronics, Smart Hardware, Digital Systems, RISE Research Institutes of Sweden, 60233 Norrköping, Sweden.
Sensors (Basel). 2024 Jun 6;24(11):3678. doi: 10.3390/s24113678.
Hydrogels are of great importance for functionalizing sensors and microfluidics, and poly(ethylene glycol) dimethacrylate (PEG-DMA) is often used as a viscosifier for printable hydrogel precursor inks. In this study, 1-10 kDa PEG-DMA based hydrogels were characterized by gravimetric and electrochemical methods to investigate the diffusivity of small molecules and proteins. Swelling ratios () of 14.43-9.24, as well as mesh sizes ξ of 3.58-6.91 nm were calculated, and it was found that the correlates with the molar concentration of PEG-DMA in the ink () (SR = 0.1127 × MCI + 8.3256, R = 0.9692) and ξ correlates with the molecular weight () (ξ = 0.3382 × + 3.638, R = 0.9451). To investigate the sensing properties, methylene blue (MB) and MB-conjugated proteins were measured on electrochemical sensors with and without hydrogel coating. It was found that on sensors with 10 kDa PEG-DMA hydrogel modification, the DPV peak currents were reduced to 92 % for MB, 73 % for MB-BSA, and 23 % for MB-IgG. To investigate the diffusion properties of MB(-conjugates) in hydrogels with 1-10 kDa PEG-DMA, diffusivity was calculated from the current equation. It was found that diffusivity increases with increasing ξ. Finally, the release of MB-BSA was detected after drying the MB-BSA-containing hydrogel, which is a promising result for the development of hydrogel-based reagent reservoirs for biosensing.
水凝胶对于传感器和微流体功能化非常重要，聚（乙二醇）二甲基丙烯酸酯（PEG-DMA）常被用作可打印水凝胶前体油墨的增稠剂。在本研究中，采用重量法和电化学方法对基于1-10 kDa PEG-DMA的水凝胶进行了表征，以研究小分子和蛋白质的扩散率。计算出溶胀率（）为14.43-9.24，以及网孔尺寸ξ为3.58-6.91 nm，并且发现与油墨中PEG-DMA的摩尔浓度（）相关（SR = 0.1127 × MCI + 8.3256，R = 0.9692），而ξ与分子量（）相关（ξ = 0.3382 × + 3.638，R = 0.9451）。为了研究传感特性，在有和没有水凝胶涂层的电化学传感器上测量了亚甲基蓝（MB）和MB偶联蛋白。结果发现，在经过10 kDa PEG-DMA水凝胶修饰的传感器上，差分脉冲伏安法（DPV）的峰值电流对于MB降低到92%，对于MB-BSA降低到73%，对于MB-IgG降低到23%。为了研究MB（-偶联物）在1-10 kDa PEG-DMA水凝胶中的扩散特性，根据电流方程计算了扩散率。结果发现扩散率随着ξ的增加而增加。最后，在干燥含MB-BSA的水凝胶后检测到了MB-BSA的释放，这对于开发用于生物传感的基于水凝胶的试剂库来说是一个很有前景的结果。
