Bifunctional Diblock DNA-Mediated Synthesis of Nanoflower-Shaped Photothermal Nanozymes for a Highly Sensitive Colorimetric Assay of Cancer Cells

Abstract

The activity of a nanozyme is closely related to its surface area-to-volume ratio and the surrounding temperature. To acquire highly active nanozymes, one-pot metallization-like synthesis of novel nanoflower-shaped photothermal nanostructures was conducted using polyadenine-containing diblock DNA as the scaffold. The nanoflower-shaped structures with a high surface area-to-volume ratio and photothermal performance exhibited excellent peroxidase-mimicking activity, and the biorecognition capability was retained by the capping agent of diblock DNA. The functionalized nanostructures were used for a proof-of-concept colorimetric assay of cancer cells in vitro. Upon incorporation of 808 nm laser irradiation, high sensitivity and selectivity for the cancer cell assay were achieved with the lowest detection level of 10 cells/mL. Relative to spherical gold nanostructures, the nanoflower-shaped photothermal nanozyme exhibited higher assay sensitivity, paving the way for the construction of nanozyme-based colorimetric sensors for point-of-care testing.

A photonanozyme with light-empowered specific peroxidase-mimicking activity

“…[30][31][32] The essential of them is that only the ligand molecules or modification materials around the nanozymes are controlled by light for strengthening or weakening the catalytic activity, while the nanozymes themselves always hold the intrinsic property for catalysis. 33,34 In addition, unlike photocatalysis that happened over photoenzymes, in the above mentioned photo-controlled thermocatalytic systems, light is never be employed as the direct source of energy for driving the chemical conversion, although some nanomaterials (such as semiconductors and precious metal nanoparticles) are accompanied with photogeneration of reactive oxygen species under light stimulation.…”

DNA Nanotechnology-Enabled Fabrication of Metal Nanomorphology

“…Besides, they found that the length of DNA had little effect on the morphology of AgNPs. Subsequently, ssDNA sequences regulate the form of other shapes of metal nanoparticles (i.e., gold nanoflowers [64]), and bimetallic nanoparticles (i.e., Pd-Au bimetallic nanostructures [65]) have been reported.…”

Nanozymes—Hitting the Biosensing “Target”

“…Further, Au NPs have been used to detect target DNA or microRNA (miRNA) using complementary nucleic acids immobilized on Au NPs which then facilitated hybridization of the nucleic acids [ 32 , 33 ]. Au NPs also have been used to detect ions and cancer cells [ 34 , 35 ] further supporting the value of this nanozyme in biological applications.…”