An Ultrasensitive and Specific Fluorescence Split-Aptasensor for D-Vp Detection Based on Target-Induced Self-Propelled 3d-Dna Walkers Coupled with Crispr-Cas12a

Abstract

Vasopressin is a nonapeptide manufactured by the nervous system's hypothalamus. Its crucial role in maintaining the body's osmotic balance, blood pressure, salt homeostasis, and renal function has been well established. Given that the biological functions of the two enantiomers of vasopressin differ significantly, it is essential to accurately identify D-vasopressin. This paper describes the development of a highly accurate and sensitive fluorescence biosensor for detecting D-VP by utilizing a D-VP-specific split aptamer. This paper describes the development of a highly precise and sensitive fluorescence biosensor for detecting D-VP by utilizing a D-VP-specific split aptamer. Furthermore, the FAM-labeled single-stranded DNA (ssDNA-FAM) experienced non-specific cleavage mediated by the activated Cas12a protein. The subsequent release of the cleaved ssDNA-FAM led to the recovery of the fluorescence intensity that had been previously quenched. Under optimal conditions, the proposed 3D-DNA walker in conjunction with the CRISPR-Cas12a fluorescence sensor exhibits excellent linearity across a concentration range of 5 ng/mL to 32.8 μg/mL, with a detection limit (LOD) as low as 0.33 ng/mL. The fluorometric sensors were employed to identify D-VP in human serum and urine samples, yielding highly satisfactory results. This unique design acts as a proof of concept and illustrates considerable promise for the detection of a wide range of analytes.

Keywords: CRISPR/Cas12a, Split aptamer, D-VP, 3D-DNA walker, Fluorescence