Multifunctional protein particles with dual analytical channels for colorimetric enzymatic bioassays and fluorescent immunoassays

Abstract

Advanced multifunctional protein particles encapsulated enzymes and antibodies were developed for enzymatic bioassays and immunoassays with colorimetric and fluorescent channels. A colorimetric channel based on colour-substrate precipitation was assigned for enzymatic bioassays for the measurement of hydrogen peroxide with the lowest detectable concentration of 10 µM. A fluorescent channel based on fluorescent labeled antibodies was assigned for immunoassays for the measurement of mouse immunoglobulin G (M IgG) with the lowest detectable concentration of 1.25 µg L -1 . The protein microparticles were fabricated with a template-assisted self-assembly technique termed "Protein Activation Spontaneous Self-assemble" (PASS). The multifunctional protein particles prepared with the PASS method have the advantages of high loading of analytical biomolecules, integrated biological functions, porous structure, and more importantly, they are optically transparent and fluorescence inactive. These unique features make our protein particles a new generation of bead-based platforms to perform enzyme bioassays and immunoassays.

Printable Heterostructured Bioelectronic Interfaces with Enhanced Electrode Reaction Kinetics by Intermicroparticle Network

“…The biological module (BSA-GOxMP) and transducer module (POM–PPyMP) were prepared using a generic CaCO 3 template-assisted technique. The porous structure and inorganic nature of the CaCO 3 allows the effective loading of various small organic, inorganic, and biological molecules such as monomer (i.e., pyrrole), electrocatalyst–Dawson-type polyoxometalate (POM), or enzyme (e.g., glucose oxidase GOx), thus providing a universal method for fabrication of microparticles with different chemical natures. − The macroscopic morphologies of the BSA-GOxMPs and POM–PPyMPs were characterized by optical microscopy. Optical images showed that the BSA-GOxMPs and POM–PPyMPs exhibited a fairly uniform spherical shape and a homogeneous narrow size distribution (Figure A,B) with an average diameter of 2.3 ± 0.3 μm and 2.6 ± 0.4 μm, respectively (Figure S1).…”

“…The BSA-GOxMP was prepared by a template-assisted protein cross-linking method. , In brief, a solution containing 450 μL of BSA solution (20 mg mL –1 ), 50 μL of GOx (10 mg mL –1 ), and 500 μL of calcium chloride (0.5 M) was rapidly mixed with 1 mL of sodium carbonate solution (0.5 M) with stirring at 600 g for 30 s to produce BSA-GOx-loaded calcium carbonate (CaCO 3 ) microparticle. The BSA-GOx-loaded calcium carbonate (CaCO 3 ) microparticles were washed three times with PBS (10 mM, pH 7.2) by centrifugation (800 g , 2 min) followed by redispersion.…”

Bioinspired protein microparticles fabrication by peptide mediated disulfide interchange

“…Scientists are looking for new biomaterials particularly in microparticle formulation for emerging medical, pharmaceutical and biological applications. [1][2][3][4][5][6] Proteins are excellent natural building blocks to prepare microparticles due to their versatile functionalities and good biocompatibility. 7 Many studies have been focused on the preparation of protein microparticles with controlled size distribution, porosity and composition; 7,8 while the extensive use of synthetic crosslink chemicals during the fabrication process remains one of the major challenges for preparing such protein microparticles for practical biomedical applications.…”

An ultrasensitive label-free electrochemical immunosensor based on signal amplification strategy of multifunctional magnetic graphene loaded with cadmium ions

“…In recent years, various detection assays have been developed for the detection of IgG, such as chemiluminescence 6 , colorimetric sensors 7 8 , fluorescence 9 10 and electrochemical immunosensors 11 12 . In comparisons, electrochemical immunoassay may be an excellent candidate for the detection of tumor markers because of fast analytical time, low detection limits, high sensitivity, simple pretreatment procedure and inexpensive instrumentation 13 14 .…”