Pristine NiMOF Sandwiched between 1D and 3D Engineered Au Particles and Dendrites for Ultraswift Folic Acid Sensing in Cellular Microenvironment

Abstract

Catalytic metal-organic frameworks (MOFs)-based sensor matrices can act synergistically with Au metallic nanostructures to generate amplified signal readouts by causing the electro-oxidation of the target analyte. Folic acid (FA), an essential water-soluble vitamin and a precursor for enzymes, requires timely and precise monitoring in the serum of individuals with varying clinical diagnoses. An attempt has been made in this direction through our work, where the rapid detection of FA through its oxidation at metal centers from hybrid nanomaterials is deployed for signal generation. A nonenzymatic, nonimmunometric approach involving a sandwich model, comprising NiMOF layered between gold nanoparticles (AuNPs) and gold nanodendrites (AuNDs) incorporated within a sensor matrix, has been deployed for this purpose. The probe displayed great analytical performance with a linear dynamic range (LDR) from 1 × 10^–11 M to 1 × 10^–3 M and a limit of detection (LOD) of 0.43 × 10^–11 M. The probe’s average response time with respect to changes in FA concentration was recorded as less than 2.1 s, making it a rapid sensing platform for FA detection. The real-life applicability of the developed sensor was tested in serum, followed by analysis in a breast cancer cellular microenvironment, which yielded a current recovery between 95.11 and 98.17%. The in vitro analysis was further validated through live-cell imaging using the standard method of fluorescence. The shorter fabrication time of the developed sensor compared to existing ones makes it a facile and efficient sensing platform for FA detection in clinical settings. This study represents the first report on the conjunction of 1D, 2D, and 3D materials as a sensing matrix for molecular detection applications.