The essential properties of a biosensor are its sensitivity and selectivity to detect, monitor and quantify the biomarker(s) for the interests of medicine. Bio-recognition mechanism is the core element of a biosensor. New designs and methods for advancing the sensitivity and selectivity of a bio-recognition mechanism of a biosensor are scientifically and practically relevant and significant.
A conventional bio-recognition element, such as an antibody, realizes its sensing function through molecular interactions. The downstream transduction of this sensing signal relies on externally designed strategies, such as surface impedance or light scattering [1]. In contrast, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a programmable gene editing tool that provides the capability to realize targeted cleavage of nucleic acids [2], thereby the nature of CRISPR Cas systems is collective machinery for sensing and actuating [3]. This advantage of CRISPR Cas systems allows engineers to design simple interfaces and molecular circuits to utilize the programmability of CRISPR to detect a wide range of targets of interest, from proteins to nucleic acids [4,5,6,7,8,9].
This Special Issue, “Application of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) Cas Systems for Biosensing”, intends to bring awareness to and demonstrate the uniqueness of the CRISPR-Cas systems for advancing biosensing. It is hoped that the advancement of CRISPR-Cas based bio-recognition mechanism will lead to a biosensor system with excellent and improved sensitivity and selectivity. Specifically, the methods and the techniques of integrating CRISPR-Cas into various biosensing systems, the design strategies of a CRISPR-Cas system in a biosensor, and the integration between conventional nucleic acid probe-based recognition elements and CRISPR-based recognition elements require additional research and development endeavors. Thus, expanding scientific research and development efforts by biosensor researchers for CRISPR-Cas-based biosensing systems are timely and important to translational biomedical science. Different CRISPR-Cas biosensing systems are described in the manuscripts of this Special Issue, demonstrating the applicability of a CRISPR-Cas system in biosensing. Furthermore, various methods and techniques in cooperating the CRISPR-Cas system into a completed biosensor system are discussed and presented. The research discussed in this Special Issue exhibits the utilization of a CRISPR-Cas biosensing system for detecting different biomarkers and/or measuring a special need.
Specifically, in this issue, Arold S. et al. described a systematic guideline on selecting the right CRISPR systems for in vitro application [10], which provides a tutorial for researchers to design and engineer CRISPR for diverse in vitro applications. To understand the performance of CRISPR-Cas 9 on genome engineering [11], Ozsoz M. et al. developed a carbon nanotube-based electrochemical genosensor capable of detecting mutations introduced by Cas9. Liang, D. et al. designed a Cas12a-based lateral flow assay to detect spinal muscular atrophy [12]. Liang, D. et al. further demonstrated using Cas14a to detect the same disease [13]. Liang, Q. et al. interfaced optogenetic control and CRISPR to engineer a novel approach to modulate metabolic burden [14]. These works showcase the diverse capabilities of CRISPR-Cas-based systems for engineering and medicine.
Acknowledgments
We are honored and grateful to have the opportunity to serve as the Guest Editors of this Special Issue. We thank all the authors who contribute to this Special Issue by providing excellent research and inspiration to CRISPR-Cas biosensing technology. We also thank the editorial and publishing staff of Biosensors and MDPI for their dedicated and kind assistance in preparing this Special Issue.
Conflicts of Interest
The authors declare no conflict of interest.
Funding Statement
This research received no external funding.
Footnotes
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
References
- 1.Dai Y., Liu C.C. Recent Advances on Electrochemical Biosensing Strategies toward Universal Point-of-Care Systems. Angew. Chem. Int. Ed. 2019;58:12355–12368. doi: 10.1002/anie.201901879. [DOI] [PubMed] [Google Scholar]
- 2.Chen J.S., Doudna J.A. The chemistry of Cas9 and its CRISPR colleagues. Nat. Rev. Chem. 2017;1:0078. doi: 10.1038/s41570-017-0078. [DOI] [Google Scholar]
- 3.Dai Y., Wu Y., Liu G., Gooding J.J. CRISPR Mediated Biosensing Toward Understanding Cellular Biology and Point-of-Care Diagnosis. Angew. Chem. Int. Ed. 2020;59:20754–20766. doi: 10.1002/anie.202005398. [DOI] [PubMed] [Google Scholar]
- 4.Liang M., Li Z., Wang W., Liu J., Liu L., Zhu G., Karthik L., Wang M., Wang K.F., Wang Z., et al. A CRISPR-Cas12a-derived biosensing platform for the highly sensitive detection of diverse small molecules. Nat. Commun. 2019;10:3672. doi: 10.1038/s41467-019-11648-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Li Y., Liu L., Liu G. CRISPR/Cas Multiplexed Biosensing: A Challenge or an Insurmountable Obstacle? Trends Biotechnol. 2019;37:792–795. doi: 10.1016/j.tibtech.2019.04.012. [DOI] [PubMed] [Google Scholar]
- 6.Kempton H.R., Goudy L.E., Love K.S., Qi L.S. Multiple Input Sensing and Signal Integration Using a Split Cas12a System. Mol. Cell. 2020;78:184–191. doi: 10.1016/j.molcel.2020.01.016. [DOI] [PubMed] [Google Scholar]
- 7.Xu W., Jin T., Dai Y., Liu C.C. Surpassing the detection limit and accuracy of the electrochemical DNA sensor through the application of CRISPR Cas systems. Biosens. Bioelectron. 2020;155:112100. doi: 10.1016/j.bios.2020.112100. [DOI] [PubMed] [Google Scholar]
- 8.Dai Y., Somoza R.A., Wang L., Welter J.F., Li Y., Caplan A.I., Liu C.C. Exploring the Trans-Cleavage Activity of CRISPR-Cas12a (cpf1) for the Development of a Universal Electrochemical Biosensor. Angew. Chem. Int. Ed. 2019;58:17399–17405. doi: 10.1002/anie.201910772. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Dai Y., Xu W., Somoza R.A., Welter J.F., Caplan A.I., Liu C.C. An Integrated Multi-Function Heterogeneous Biochemical Circuit for High-Resolution Electrochemistry-Based Genetic Analysis. Angew. Chem. Int. Ed. 2020;59:20545–20551. doi: 10.1002/anie.202010648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Díaz-Galicia E., Grünberg R., Arold S.T. How to Find the Right RNA-Sensing CRISPR-Cas System for an In Vitro Application. Biosensors. 2022;12:53. doi: 10.3390/bios12020053. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Kivrak E., Pauzaite T., Copeland N.A., Hardy J.G., Kara P., Firlak M., Yardimci A.I., Yilmaz S., Palaz F., Ozsoz M. Detection of CRISPR-Cas9-Mediated Mutations Using a Carbon Nanotube-Modified Electrochemical Genosensor. Biosensors. 2021;11:17. doi: 10.3390/bios11010017. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Zhang C., Li Z., Chen M., Hu Z., Wu L., Zhou M., Liang D. Cas12a and Lateral Flow Strip-Based Test for Rapid and Ultrasensitive Detection of Spinal Muscular Atrophy. Biosensors. 2021;11:154. doi: 10.3390/bios11050154. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Hu Z., Chen M., Zhang C., Li Z., Feng M., Wu L., Zhou M., Liang D. Cas14a1-Mediated Nucleic Acid Diagnostics for Spinal Muscular Atrophy. Biosensors. 2021;12:268. doi: 10.3390/bios12050268. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Li X., Jiang W., Qi Q., Liang Q. A Gene Circuit Combining the Endogenous I-E Type CRISPR-Cas System and a Light Sensor to Produce Poly-β-Hydroxybutyric Acid Efficiently. Biosensors. 2022;12:642. doi: 10.3390/bios12080642. [DOI] [PMC free article] [PubMed] [Google Scholar]