Pengcheng Gao/Fan Xia's Group Functional molecules on the outer surface of nanochannels regulate ions transport

Pengcheng Gao/Fan Xia's Group Functional molecules on the outer surface of nanochannels regulate ions transport

Nanochannel-systems are artificial passages of ions and molecules with unique controllable performances. They have been widely used in sensing, drug release, separation, nanofluidic, nanoelectrochemistry, and energy conversion, owing to their adjustable geometries at the nanoscale, versatile chemical compositions, and strong mechanical strength.

Currently, both theoretical and experimental investigation showed the synergistic effects of functional molecules on the outer surface of nanochannels on regulating-ion-transport in the presence of functional molecules on the inner wall. Compared with the confined space in nanochannel, relatively more free-spaces of outer surface endow functional molecules with advanced characteristics, such as easy to immobilize, available for precise characterizations, receptive for foreign substrates, and potential application in new scenarios. However, till now the properties of most functional molecules are still inexplicit or generally presumed from the measurable functional molecules on the outer surface of nanochannels, which would bring potential errors.

Focusing on the above problems, Gao/Xia's group reported a series of functional nanochannels with well-defined probes on the outer surface. These nanochannels have shown promising results in bioanalyses because the outer surface is easy to reach for foreign targets, even with a size bigger than the pore size. The experiments demonstrated that the charged targets captured on the outer surface did not bring obvious rise in the internal resistance of nanochannels, but instead greatly increased the ionic current. Thus, it could potentially tackle the inefficiencies of the ionic signal conversion resulted from the offset between the space charge and steric effect of targets. These results challenge the essential role of steric hindrance on the ionic signal and described the core parameter — potential distribution affecting ions transport.

The article was published in Nature Communications under the title "Towards explicit regulating-ion-transport: nanochannels with only function-elements at outer-surface".

This research was supported by the National Natural Science Foundation of China. Prof. Pengcheng Gao and Prof. Fan Xia from China University of Geosciences (Wuhan) are the corresponding authors of this work, and the first author is Dr. Qun Ma from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1038/s41467-021-21507-7

In recent years, Prof. Pengcheng Gao/Prof. Fan Xia's group has focused on functionalization of the outer surface of nanochannels. In 2021-2022, a paper has been published in Nature Communications, a paper has been published in Nature Protocols and four papers have been published in Analytical Chemistry.

1. "Regional and functional division of functional elements of solid-state nanochannels for enhanced sensitivity and specificity of biosensing in complex matrices". Nature Protocols 2021, 16, 4201. Prof. Fan Xia from China University of Geosciences (Wuhan) is the corresponding author of this work, and the first author is Prof. Pengcheng Gao from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1038/s41596-021-00574-6

2. "Revealing Ionic Signal Enhancement with Probe Grafting Density on the Outer Surface of Nanochannels". Analytical Chemistry 2021, 93, 13054. Prof. Pengcheng Gao from China University of Geosciences (Wuhan) is the corresponding author of this work, and the first author is graduated student Tianle Liu from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1021/acs.analchem.1c03010

3. "Exponential Increase in an Ionic Signal: A Dominant Role of the Space Charge Effect on the Outer Surface of Nanochannels". Analytical Chemistry 2021, 93, 13711. Prof. Pengcheng Gao from China University of Geosciences (Wuhan) is the corresponding author of this work, and the first author is master student Xiaoqing Wu from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1021/acs.analchem.1c03431

4. "Ionic Signal Enhancement by the Space Charge Effect through the DNA Rolling Circle Amplification on the Outer Surface of Nanochannels". Analytical Chemistry 2021, 93, 16043. Prof. Pengcheng Gao from China University of Geosciences (Wuhan) is the corresponding author of this work, and the first author is master student Xiaoqing Wu from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1021/acs.analchem.1c03631

5. "Polydopamine-Induced Modification on the Highly Charged Surface of Asymmetric Nanofluidics: A Strategy for Adjustable Ion Current Rectification Properties". Analytical Chemistry 2022, 94, 2493. Prof. Pengcheng Gao from China University of Geosciences (Wuhan) is the corresponding author of this work, and the first author is Ph.D student Zhixiao Si from China University of Geosciences (Wuhan).

Article link: https://doi.org/10.1021/acs.analchem.1c04323

Figure 1. Three stages of designed nanochannel-systems developed by Prof. Pengcheng Gao/Prof. Fan Xia's group