The application of DNA polymerases and Cas9 as representative of DNA-modifying enzymes group in DNA sensor design (review)

Julija Dronina^a,b, Urte Samukaite Bubniene^b, Arunas Ramanavicius^b

Laboratory of Nanotechnology, Department of Functional Materials and Electronics, Center for Physical Sciences and Technology, Sauletekio av. 3, Vilnius, Lithuania.

Abstract

Rapid detection of nucleic acids (DNA or RNA) by inexpensive, selective, accurate, and highly sensitive methods is very important for biosensors. DNA-sensors based on DNA-modifying enzymes for fast determination and monitoring of pathogenic (Zika, Dengue, SARS-Cov-2 (inducer of COVID-19), human papillomavirus, HIV, etc.) viruses and diagnosis of virus-induced diseases is a key factor of this overview. Recently, DNA-modifying enzymes (Taq DNA polymerase, Phi29 DNA polymerase) have been widely used for the diagnosis of virus or pathogenic disease by gold standard (PCR, qPCR, RT-qPCR) methods, therefore, alternative methods have been reviewed. The main mechanisms of DNA metabolism (replication cycle, amplification) and the genomeediting tool CRISPR-Cas9 are purposefully discussed in order to address strategic possibility to design DNA-sensors based on immobilized DNA-enzymes. However, the immobilization of biologically active proteins on a gold carrier technique with the ability to detect viral or bacterial nucleic acids is individual for each DNA-modifying enzyme group, due to a different number of active sites, C and N terminal locations and arrangement, therefore, individual protocols based on the ’masking’ of active sites should be elaborated for each enzyme.

Keywords: Biosensors, DNA-Sensors, DNA polymerases, CRISPR-Cas9, COVID-19, Gold nanoparticles.