Biomolecular Surface Functionalization and Stabilization Method to Fabricate Quantum Dots Nanobeads for Accurate Biosensing Detection

Abstract

The surface functionalization of quantum dots (QDs) is essential for their application as a label material in a biological field. Here, a protein surface functionalization approach was introduced to combine with silica encapsulation for the sustainable and stable synthesis of QDs nanobeads for biomarker detection. The formation of QDs nanobeads was achieved by multiple mercapto groups in bovine serum albumin (BSA) macromolecules as multidentate ligands to replace hydrophobic ligands on the surface of QDs and decompression. The resulting QDs nanobeads exhibited 20 times more photoluminescence than the corresponding hydrophobic QDs and presented excellent stability under physiological conditions due to the protection of BSA and silica. The nanobeads served as a robust signal-generating reagent to construct the lateral flow immunoassay (LFIA) biosensor for the detection of glycosylated hemoglobin (HbA1c). The concentration of HbA1c was determined within 10 min with high specificity using only 60 μL of whole blood samples collected clinically. The nanobeads-based LFIA biosensor exhibited linear detection of HbA1c from 4.2% to 13.6%. The accuracy and stability of this approach in clinical utility was demonstrated by the detection of HbA1c after a long-term storage of test strips. This protein surface modification technology provides a new way for improving the biological properties of QDs in clinical diagnosis.

Bio-Tailored Sensing at the Nanoscale: Biochemical Aspects and Applications

“…Optical immunosensors based on papers and pads for visive colorimetric and/or fluorescence detection are also reported. An example describes how hydrophobic QDs can be coupled to protein moieties to increase both the solubility and fluorescence and detect glycosylated hemoglobin in blood samples as reported by Li et al [ 116 ] ( Figure 17 ). In this study, wet chemical synthesis of oleic acid-capped CdSe-ZnSQDs is realized and the resulting material is mixed in chloroform with bovine serum albumin under ultrasonication conditions at various QDs:protein ratios.…”

“…A double fluorescent signal is detected; otherwise, in the absence of the analyte only the control fluorescent band is visible. Image adapted from [ 116 ] with permission of American Chemical Society, 2022.…”

Development of a Dual Fluorescence Signal-Enhancement Immunosensor Based on Substrate Modification for Simultaneous Detection of Interleukin-6 and Procalcitonin

“…Quantum dots (QDs) are ideal optical labels for highly sensitive multiple detection in in vitro diagnostics (IVD) due to their unique optical properties. , Optical biosensors based on QDs have been widely used to detect a wide range of biomarkers, small molecule toxins, etc . − The accuracy and sensitivity of obtaining more biological information from low volume will be the future trend in the development of quantitative detections in IVD, , especially for highly sensitive and disease-specific biomarker detection, such as those associated with infectious diseases . A delayed early diagnosis and timely treatment of infectious diseases can result in sepsis, multiple organ dysfunction syndrome (MODS), and even life-threatening disease progression. − Procalcitonin (PCT) and Interleukin-6 (IL-6), among the many highly sensitive and specific inflammatory factors, are new effective indexes for assessing the severity of bacterial infection, determining the prognosis of the disease, evaluating the effectiveness of antibiotic use, and guiding clinical treatment .…”

Amine‐ and Polyethylene glycol‐Functionalized Pyrediyne Quantum Dots for Bioimaging Applications

“…Surface modification is one of the effective ways to alter the photoluminescence, biocompatibility, and electronic properties of various low-dimensional materials, including quantum dots (QDs). [1][2][3][4][5][6][7][8] Generally, there are two methods for the modification of QDs, namely pre-fabrication and post-fabrication modification. [9][10][11][12][13][14][15][16] Pre-fabrication can be achieved by conventional chemical reduction methods and with the assistance of UV irradiation, whereas post-fabrication modification includes surface functionalization after the preparation of QDs.…”