Outer-surface covering of nanochannels with hydrogel for anti-protein-interference on the ion current

Nanopore/nanochannel sensing is a promising analytical method in the fields of chemistry and biology. However, due to the interference of non-analytes in complex samples, directly analyzing un-pretreated samples through nanopores/nanochannels remains a great challenge. Here, we report a type of heterogeneous membrane by covering anodic aluminum oxide (AAO) cylindrical nanochannel porous membrane with graphene oxide/calcium alginate (GCA) hybrid hydrogel to reduce the interference of protein on the current detection signal. The hydrogel layer blocks the protein through steric hindrance, so that it will not block and affect the channel. The results show that when the GCA hydrogel is covered on the outer surface of AAO membrane, the interference of protein on the ion current decreases from 52 % to 5 %. Our work provides a strategy for reducing the interference of non-analytes in complex samples, and demonstrates the anti-interference function of hydrogels on nanopore/nanochannel sensing.