Nanopipettes—The past and the present

John Stanley,Nader Pourmand

doi:10.1063/5.0020011

Abstract

Nanopipettes, characterized by nanoscale sized pores and simple fabrication techniques, are of increasing scientific interest due to their application in a variety of fields, including analytical chemistry, nanophysiology, molecular diagnostics, and cellular biology. Nanopipettes have been extensively used for the development of electrochemical biosensors, as they offer the combined advantage of nanoscale dimensions and the selectivity and sensitivity of conventional solid-state biosensors. Over the years, with advances in technology and the expansion of research interests, functionalized nanopipettes have been successfully employed for performing real-time quantitative measurement of changes within a single cell. They have also been routinely used to aspirate/inject attoliter to picoliter volumes at intracellular levels and have become the “go-to” tools for cutting-edge research in molecular and cell biology. The use of nanopipettes as probes for imaging soft materials through scanning probe microscope (SPM) techniques such as scanning electrochemical microscopy and scanning ion-conductance microscopy has been widely explored. Advances in both the technical and theoretical aspects of nanopipette technology have a profound impact on early diagnosis and treatment of various diseases including cancer, diabetes, and Alzheimer’s. In this review, we provide insights into the fabrication, morphological, and electrochemical characterization of the nanopipette and comprehensively discuss the various applications available in the literature of nanopipettes as sensing probes, monitoring probes for single cells, and SPMs.

Highlights

The use of narrow glass tubes in biology has been reported since the discovery of capillary action in the 16th century
Glass pipettes with pore diameters ranging from the micro- to nanoscale are being extensively used in a wide variety of research including analytical chemistry, molecular and cell biology, and sensor development
Researchers have developed an scanning electrochemical microscopy (SECM) that can provide information about heterogeneous electron transfer kinetics as well as reaction imaging.[78]. This was achieved by combining reagent delivery through the nanopipette with the SECM technique that generally involves the study of electron transfer at the conductive substrate and ion transfer across the liquid/liquid interface supported at the nanopipette tip

Summary

Introduction

The use of narrow glass tubes in biology has been reported since the discovery of capillary action in the 16th century. One of the simplest methods of sensing using nanopipettes relies on the observation of changes in ion current rectification (ICR) when molecules translocate through the pore.[5,14] Over the years, the selectivity and sensitivity of the nanopipette based sensor have been drastically improved by modifying the inner surface of the pipette.

Results

Conclusion