Brilliant Pitaya‐Type Silica Colloids with Central–Radial and High‐Density Quantum Dots Incorporation for Ultrasensitive Fluorescence Immunoassays

Abstract

Creating secondary nanostructures from fundamental building blocks with simultaneous high loading capacity and well-controlled size/uniformity, is highly desired for nanoscale synergism and integration of functional units. Here a novel strategy is reported for hydrophobic quantum dots (QDs) assembley with porous templates, to form pitaya-type fluorescent silica colloids with densely packed and intact QDs throughout the silica matrix. The mercapto-terminated dendritic silica spheres with highly accessible centralradial pores and metal-affinity interior surface, are adopted as a powerful absorbent host for direct immobilization of QDs from organic phase with high loading capacity. The alkylsilane mediated silica encapsulation prevents QDs' optical degradation induced by ligand exchange and favors the homogeneous silica shell formation. These multiple QD embedded silica spheres exhibit good compatibility for different colored QDs with well-preserved fluorescence, high colloidal/optical stability, and versatile surface functionality. It is demonstrated that after integration with a lateral flow strip platform, these silica colloids provide an ultrasensitive, specific, and robust immunoassay for C-reaction protein in clinical samples as promising fluorescent reporters.

CsPbBr3‐Quantum‐Dots/Polystyrene@Silica Hybrid Microsphere Structures with Significantly Improved Stability for White LEDs

“…Among various macromolecule polymers, mesoporous polystyrene microspheres (MPMs), with large surface areas and deep crosslinking channels, are ideal platforms for large‐volume loading of fluorescent QDs . Compared with inorganic mesoporous microspheres such as Al 2 O 3 and TiO 2 , MPMs can provide more anchoring points for PQDs, which is very helpful for immobilizing these PQDs within the crosslinking channels and forming robust PQD/MPMs composite structures.…”

Ultrasensitive Detection of Severe Fever with Thrombocytopenia Syndrome Virus Based on Immunofluorescent Carbon Dots/SiO2 Nanosphere-Based Lateral Flow Assay

“…23 Over the past decade, many researchers have worked on the construction and application of semiconductor QDs-based fluorescence nanospheres and have achieved a series of achievements. 24−31 Different construction methods always have various limitations. 23,32 For instance, after embedding high-quality oil QDs into nanospheres, QDs may leak out of the sphere pores in nonpolar suspended media.…”

Synthesis of polystyrene-based fluorescent quantum dots nanolabel and its performance in H5N1 virus and SARS-CoV-2 antibody sensing

“…QDs encapsulation in silica nanobeads is an alternative widely adopted as signal amplification materials for the development of bioassay with improved sensitivity [ [18] , [19] , [20] , [21] , [22] , [23] , [24] ]. Typically, the synthesis fluorescence nanobeads involves the immobilization of QDs on the surface of colloidal silica realized by amino-group mediated electrostatic interaction or thiol-group driven coordination, followed by silica shell coating for the purpose of fluorescence stabilization and functionalization.…”

“…Typically, the synthesis fluorescence nanobeads involves the immobilization of QDs on the surface of colloidal silica realized by amino-group mediated electrostatic interaction or thiol-group driven coordination, followed by silica shell coating for the purpose of fluorescence stabilization and functionalization. To data, nonporous [ [18] , [19] , [20] , [21] , [22] ] and dendritic silica [ 23 , 24 ] are the chief templates for QDs assembly, among which dendritic silica featured with ultralarge pore channels and highly accessible inner surface exhibits obvious superiority for QDs loading and application in sensitive bioassay as compared with its counterparts. In addition, polystyrene (PS) bead, due to its sophisticated synthesis technique, is the core material commonly served as the suspension carrier for the immobilization of capture antibody in the above mentioned techniques [ 7 ].…”