Chip-Based and Wearable Tools for Isothermal Amplification and Electrochemical Analysis of Nucleic Acids

Abstract

The determination of nucleic acids has become an analytical diagnostic method with many applications in fields such as biomedical sciences, environmental monitoring, forensic identification, and food safety. Among the different methods for nucleic acid analysis, those based on the polymerase chain reaction (PCR) are nowadays considered the gold standards. Isothermal amplification methods are an interesting alternative, especially in the design of chip-based architectures. Biosensing platforms hold great promise for the simple and rapid detection of nucleic acids since they can be embedded in lab-on-a-chip tools to perform nucleic acid extraction, amplification, and detection steps. Electrochemical transduction schemes are particularly interesting in the design of small and portable devices due to miniaturization, low-energy consumption, and multianalyte detection capability. The aim of this review is to summarize the different applications of isothermal amplification methods combined with electrochemical biosensing techniques in the development of lab-on-a-chip tools and wearable sensors. Different isothermal amplification methods are revised, and examples of different applications are discussed. Finally, a discussion on patented devices is also included.

Nucleic Acid Amplification‐Based Technologies (NAAT)—Toward Accessible, Autonomous, and Mobile Diagnostics

“…For truly at-home, or mobile diagnostics, continued progress toward miniaturization can enable ultraportability in remote or field settings. [131,132] Continuous or frequent operation for cases such as environmental surveillance in remote settings would require minimal power usage by devices, to enable long-term operation. Minimizing the number of non-reusable components will be helpful to improve the product's sustainability and avoid supply-chain issues for deliveries.…”

Strategies for the Voltammetric Detection of Loop-Mediated Isothermal Amplification

“…Despite these advances, however, PCR still has a relatively long time-to-detection, and the requirement for thermocycling increases device complexity. As a possible solution to these shortcomings, isothermal amplification techniques are becoming increasingly popular in the development of point-of-use devices [ 9 , 10 , 11 ]. Of the many isothermal amplification techniques thus far developed, loop-mediated isothermal amplification (LAMP) has become popular due to its rapid, high-efficiency amplification of very low copy numbers of the template, and the theoretical potential for very high specificity [ 12 ].…”