Electrochemical Detection and Point-of-Care Testing for Circulating Tumor Cells: Current Techniques and Future Potentials

Abstract

Circulating tumor cells (CTCs) are tumor cells that escaped from the primary tumor or the metastasis into the blood and they play a major role in the initiation of metastasis and tumor recurrence. Thus, it is widely accepted that CTC is the main target of liquid biopsy. In the past few decades, the separation of CTC based on the electrochemical method has attracted widespread attention due to its convenience, rapidness, low cost, high sensitivity, and no need for complex instruments and equipment. At present, CTC detection is not widely used in the clinic due to various reasons. Point-of-care CTC detection provides us with a possibility, which is sensitive, fast, cheap, and easy to operate. More importantly, the testing instrument is small and portable, and the testing does not require specialized laboratories and specialized clinical examiners. In this review, we summarized the latest developments in the electrochemical-based CTC detection and point-of-care CTC detection, and discussed the challenges and possible trends.

Tailored point-of-care biosensors for liquid biopsy in the field of oncology

“…34 Electrochemical detection of numerous liquid biopsies for cancer has been the topic of discussion in a number of very good reviews; however, the majority of these studies mostly focused on single LB such as proteins, miRNA, ctDNA, exosomes, and cancer cells. 30,[35][36][37][38] A comprehensive review wrapping up the current magnificent state of the art in pointof-care (POC) and biosensor technology for all LB markers is currently awaiting publication in a single report. Consequently, the aim of this article is to provide a comprehensive summary of literature published in recent years on the development of LB biosensors and technical approaches to their use in healthcare and their management.…”

Basic Principles and Recent Advances in Magnetic Cell Separation

“…The convenient and noninvasive sampling of CTCs from blood, or "liquid biopsy" offers opportunities for the development of new platforms for point-of-care disease screening [247][248][249], also accessible in low-resource settings. Yang et al combined a dual recognition strategy and glucometer-based signal readout to develop a point-of-care approach for detecting CTCs in whole blood [250].…”

From Small Molecules toward Whole Cells Detection: Application of Electrochemical Aptasensors in Modern Medical Diagnostics

“…One of the possible, and still more and more popular, is the use of electrochemical aptasensors as detection elements in such. This is especially driven by the microelectronics progress and digitalization of the surrounded world, which led, e.g., to the production of miniaturized handheld point-of-care (PoC) devices [ 191 , 192 , 193 , 194 , 195 ]. Such a medical diagnostic development is of special interest as in an aging society, improvement of quality of life is one of the most important goals.…”

“…In turn, this would significantly increase the awareness of the current health status of an individual person, and the same time, it would reduce the time necessary to implement appropriate medical procedures. Such devices, in comparison to traditional laboratory procedures, offer significantly reduced sample volume and shorter detection time, improved sensitivity due to high surface to volume ratio (also surface modified with carefully chosen nanomaterials), high throughput by parallel operation, portability, and disposability and what is no less important also real-time detection and an automated measurement process [ 191 , 192 , 193 , 194 , 195 ].…”