School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
Carbohydr Polym. 2024 Feb 15;326:121639. doi: 10.1016/j.carbpol.2023.121639. Epub 2023 Nov 28.
A novel hydrogel humidity sensor was developed using acrylic acid/bagasse cellulose (AA/BC) porous hydrogel triggered by cold plasma (CP) combining graphene oxide (GO) and embedding citral for antibacterial and intelligent fruit preservation. Results showed that both GO and citral were loaded in AA/BC and had strong hydrogen bond interaction with hydrogel. Acrylic acid/bagasse cellulose/graphene oxide (AA/BC/GO) showed the highest humidity response when the compound concentration of GO was 1.0 mg/mL and the test frequency was 1 kHz, and exhibited high electrical conductivity (-2.6 mS/cm). In addition, in continuous and cyclic relative humidity (RH) tests, the response time of AA/BC/GO from 33.70 % RH to 75.30 % RH was about 177.4 s and the recovery time was about 150.6 s, with excellent sensitivity and durability. The sensors also revealed remarkable antibacterial properties against Escherichia coli and Staphylococcus aureus, among which acrylic acid/bagasse cellulose/graphene oxide-citral (AA/BC/GO-C) was the most prominent, and could extend the shelf life of mangoes for about 8 days. By intuitively judging the appearances and total color difference (TCD) of the hydrogel sensors, it could play the role of intelligent preservation by connecting their water absorption and the release of citral. Therefore, this work provided innovative strategies for the application of hydrogel sensors in food preservation.
一种新型水凝胶湿度传感器采用丙烯酸/蔗渣纤维素（AA/BC）多孔水凝胶通过冷等离子体（CP）触发制备，该水凝胶结合了氧化石墨烯（GO）并嵌入柠檬醛以实现抗菌和智能水果保鲜。结果表明，GO 和柠檬醛均负载于 AA/BC 中，并与水凝胶具有强烈的氢键相互作用。当 GO 的复合浓度为 1.0 mg/mL，测试频率为 1 kHz 时，AA/BC/GO 表现出最高的湿度响应，其电导率高达-2.6 mS/cm。此外，在连续和循环相对湿度（RH）测试中，AA/BC/GO 从 33.70% RH 到 75.30% RH 的响应时间约为 177.4 s，恢复时间约为 150.6 s，具有出色的灵敏度和耐久性。该传感器还表现出对大肠杆菌和金黄色葡萄球菌的显著抗菌性能，其中 AA/BC/GO-柠檬醛（AA/BC/GO-C）最为突出，可将芒果的保质期延长约 8 天。通过直观判断水凝胶传感器的外观和总色差（TCD），可以通过其吸水性和柠檬醛的释放来实现智能保鲜。因此，这项工作为水凝胶传感器在食品保鲜中的应用提供了创新策略。
