Physical Adsorption Method Research Articles

Green approaches for the fabrication of electrospun poly (vinyl alcohol) nanofibers loaded epidermal growth factor derivative

Here, PVA nanofibers were electrospun from aqueous solution, then stabilized in ethanol and crosslinked by heat treatment without using any toxic solvents during the whole manufacture process. After that, the crosslinked PVA nanofiber membranes were loaded EGF by a bioorthogonal approach, which combined recombinant DNA technology with tyrosinase treatment and was also an environment friendly method. In this process, 3,4-dihydroxyphenethylamine (DOPA) was incorporated into the active site of EGF, then covalent bond was formed in the alkaline environment between EGF and PVA nanofiber membranes improving EGF binding efficiency. The cell proliferation in DOPA-EGF group was approximate 1.47 times higher than that in EGF group using traditional physical adsorption method at day 7. Therefore, this PVA nanofibers loaded DOPA-EGF using these green approaches may have a potential application in the field of wound dressing.

Antioxidant and antimicrobial activity of red propolis embedded mesoporous silica nanoparticles

This work brings the promise of MCM-41 mesoporous silica as a vehicle for red propolis for the development of controlled release drugs and delivery to a specific target site. The synthesis of MCM-41 by the sol–gel method with a pore size of approximately 3.6 nm and the incorporation of red propolis extract by the physical adsorption method in ethanolic medium were easily accomplished with around 15% encapsulation. MCM-41 and MCM-41 with red propolis (MCM-41/Pr) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermal analysis, N2 adsorption–desorption, scanning electron microscopy, and an ultra-high-performance liquid chromatography–diode array detection (UPLC-DAD). In vitro release of encapsulated red propolis was analyzed in phosphate buffer at pH 7.2, 7.4, and 7.6. An in vitro test for MCM-41/Pr antioxidant activity was performed using 2,2-diphenyl-1-picrylhydrazyl as well as analysis of antibacterial activity against Staphylococcus aureus by the well diffusion method. UPLC-DAD analysis showed that the integrity of the red propolis constituents was maintained after the embed process, and the antioxidant and antibacterial activities were preserved.

Comparative study of catalase immobilization via adsorption on P(MMA-co-PEG500MA) structures as an effective polymer support

In this study, poly[methyl methacrylate-co-poly(ethylene glycol) methacrylate] (P(MMA-co-PEG500MA)) copolymers were used for catalase (CAT) immobilization. Firstly, P(MMA-co-PEG500MA) copolymers were synthesized by using different amount of methyl methacrylate (MMA) and poly(ethylene glycol) methacrylate (PEG500MA) monomers. The synthesized copolymers were characterized by different analysis techniques. Afterward, CAT enzyme was immobilized via physical adsorption method onto the P(MMA-co-PEG500MA) copolymers. P3 sample containing 1:1 (PEG500MA:MMA) monomer molar ratio was selected as model support because of exhibiting optimum surface porosity and thermal stability. A high immobilization yield (76%) was achieved under optimized conditions. The immobilized enzyme displayed improved tolerance towards pH and temperature changes. After immobilization, the optimum pH shifted from 7.5 to 7.0, whereas the optimum temperature remained unchanged at 35 °C. Immobilized enzyme showed good reuse potential and excellent storage stability. After 10 consecutive uses, immobilized enzyme maintained about 51.0% of its initial activity. Furthermore, free enzyme completely lost its initial activity after 4 weeks, while immobilized enzyme maintained approximately 65% of the initial activity at 25 °C. Approximately twofold decrease in Km was obtained which means that the affinity of enzyme to the substrate improved after immobilization. Finally, it can be concluded that the prepared P(MMA-co-PEG500MA) copolymer structure can be an ideal matrix for CAT immobilization.

Immobilization of Cellulase from Trichoderma Reesei on Multiwall Carbon Nanotubes (MWCNTs)

Cellulase is an enzyme commonly used to break down cellulose to beta-glucose. The demand of cellulase has been arisen due to its extensive range of applications in the industries such as detergents, foods and biofuel production. In present study, cellulase from Trichoderma reesei was immobilized on a functionalized multiwall carbon nanotube (MWCNTs) by physical adsorption method. Fourier Transform Infrared (FTIR) was used to confirm the successful functionalization of MWCNTs and immobilization of cellulase. In this approach, effects of pH and temperature for both free and immobilized cellulase were evaluated. Practically, the immobilized cellulase showed an improvement in pH and thermal stability compared to free cellulase at optimum condition of 50°C and pH 5 with 12% and 8% of increments respectively. For reusability study on CMC analysis, the bionanoconjugate retained 60% of its initial activity even after 3rd cycle of analysis. This feature is beneficial to the industrial applications because of its potential to be easily separated from the end product at the end of the reaction, reuse for several times and helps in development of multiple enzyme reaction systems.

Development of paper based amperometric biosensor for glucose content measurement in Malaysian Stingless Bee Honey

Amperometric biosensor for glucose content measurement in Malaysian stingless bee honey was developed using screen printed carbon electrode (SPCE) integrated with paper disc immobilized with enzyme Glucose Oxidase (GOx) using simple physical adsorption method. The paper-based biosensor required only 8 μL of sample solution for glucose analysis. The calibration of glucose biosensor is linear between 0.5 mM to 4.5 mM (R2= 0.9925) and has a detection limit of 0.15 mM. Interference study on several compound affecting the biosensor response and storage stability was investigated. In addition, its performance was demonstrated in the analysis of six honey samples. The results obtained using glucose biosensor was validated by high performance liquid chromatographic (HPLC) method. The addition of glucose in pure honey at various concentration were also tested by this paper-based biosensor where the current obtained shows increasing trend with the addition of glucose. From this research, it can be concluded that, the prototype sensor to determine glucose adulteration in stingless bee honey was successfully developed.

All optic-fiber coupled plasmon waveguide resonance sensor using ZrS2 based dielectric layer.

We developed an all optic-fiber coupled plasmon waveguide resonance (CPWR) sensor using a zirconium disulfide (ZrS2) based dielectric layer. The dielectric constants of ZrS2 were obtained using first-principles calculations. The theoretical model of the proposed sensor was established based on the transfer matrix method, leading to the optimization of the parameters in the sensor. The sensor was fabricated by depositing a gold layer of 35 nm on the fiber core and immobilizing the ZrS2 layer on the gold layer via physical adsorption method. An experimental setup was implemented for measuring the refractive index. The sensor with two cycles showed the best performance, with a sensitivity of higher than 8000 nm/RIU.

Comprehensive kinetic and mass transfer modeling for methylene blue dye adsorption onto CuO nanoparticles loaded on nanoporous activated carbon prepared from waste coconut shell

Abstract The waste coconut shell (WCS) was used for the preparation of nanoporous activated carbon (NPAC) by chemical and physical activation method. The synthesized CuO nanoparticles were successfully loaded on the NPAC by the physical adsorption method. Different characterization techniques such as XRD, FT-IR, BET surface area, point of zero charge (pHpzc), SEM, TEM, SADE pattern, particle size distribution, and XPS were used to determine the physical-chemical properties of the CuO-NPAC nanocomposite. Thus, the prepared nanocomposites were used for methylene blue (MB) dye adsorption from aqueous solution by varying batch experimental parameters, such as initial MB dye concentration, initial pH, contact time, temperature, SDS concentration and amount of nanocomposite. In this work, a kinetic model was developed, and the developed kinetic equation was fitted with experimental data, and compared with several traditional models, such as the pseudo-second-order and Elovich models. The mass transfer mechanism was described by four diffusion models, such as Weber-Morris, liquid diffusion, Bangham's and Burt, and McKay et al. models. Adsorption equilibrium data were fitted to non-linear form of conventional isotherm models such as Langmuir, Freundlich, and Sips models, and according to high R2 values, the Sips model was best fitted followed by Langmuir and Freundlich. The possible reaction mechanism for the adsorption of MB onto the CuO-NPAC nanocomposite has also been suggested. The thermodynamic studies confirmed spontaneous adsorption of MB onto CuO-NPAC nanocomposites and showed suitability at high temperatures. The regeneration study of nanocomposite was accomplished by HCl, H2SO4, ethanol, double distilled water, and NaOH to determine the suitable reagent for the same.

Modification of cellulose nanocrystals by self-assembly nucleation agents to improve poly(L-lactide) nanocomposite’ properties

The poor thermal stability of cellulose nano-crystals (CNCs) and dispersion in polymer matrices are significant obstacles limiting their applications in modification of polymers, especially during melt processing. The self-assembly nucleation agent, decamethylene dicarboxylic dibenzoyl hydrazide (TMC300), was used to modify CNCs via physical adsorption methods. Because TMC300 adsorbed on the surface of CNCs shields the sulfonate on CNCs, the thermal stability of CNCs was significantly improved. Meanwhile, modified CNCs formed different self-assembly morphologies in confined and unconfined spaces, which influenced the crystallization behaviors and microstructures of poly(L-lactide) (PLLA). It improved the crystallization rate of PLLA, which increased the crystallinities and heat resistances of PLLA/CNC composites. More importantly, the self-assembly nucleation agent induced the shish-kebab structures of PLLA, which enhanced the interfacial structure as mechanically interfacial lock and simultaneously improved tensile strength and toughness. This physical and economical modification method of CNCs is anticipated to take full advantage of CNCs to modify PLLA or other semi-crystalline polymers via melt processing.

Development of heat transfer enhancement of a novel composite phase change material with adjustable phase change temperature

Latent thermal energy storage plays an indispensable role in exhaust heat recycles in various industries which is useful for reducing energy consumption. Different phase change temperatures and high thermal conductivities of composite phase change materials were required for various domains. In the present work, Alum as phase change material and Ala as melting point modifier, a series of phase change materials with adjustable melting temperatures were prepared by physical mixing method. Moreover, EG as porous skeleton and thermal conductive enhancer, composite with high thermal conductivity was obtained with simple physical adsorption method. The XRD and SEM were applied to characterize the phase crystal and microstructure of the composite phase change material. DSC results revealed that phase change temperatures of Alum-Ala mixtures could be adjustable from 91.11 °C to 74.61 °C and thermal conductivity of the composite was improved to 10.93 W·m−1·K−1, which is 21.9 times of pristine Alum-Ala mixture. The infrared thermography and temperature-time curves were obtained to represent the heat transfer performance and the subcooling degree intuitively. The subcooling degree was decreased from 2.238 K to 1.866 K. The result of TGA indicated that the composite possessed favorable thermal stability during the operating temperature. From the result, the composite obtained in the present work is a prospective candidate for exhaust heat recycles.

Photocatalytic Reduction of Nickel using Synthesized nano Titanium Oxide - Acidified neem saw dust Composite from Battery waste

The heavy metals, present in the battery waste water released from industries are extremely toxic and pose a serious threat to public health. The physical adsorption methods are effective, but require an additional adsorbent regeneration step. The degradation of heavy metals in industrial effluents through chemical remediation has also gained tremendous attention due to its enormous applications. Photo catalytic degradation using renewable UV / sun light is one of the most promising techniques due to its simplicity and economy. Till date, various metallic/bimetallic oxides such as TiO2, ZnO, Fe2O3 have been tested for degradation of photo catalytic components due to their superior activity, low price. Attempts have been made to study the photo catalytic degradation of heavy metals using nano Titanium Oxide and Acidified neem saw dust (nTO/ANSD) composite as a photo catalyst.In this present research, nTO/ANSD composite was synthesized and assessed for photo-chemical degradation of nickel in presence of UV light. It was observed that 96.4% Nickel was reduced using photo catalytic process. The X-Ray Diffraction(XRD) and Scanning Electron Microscopy (SEM) for nTO/ANSD studies were also performed. The recovery process of the nTO/ANSD composite photo catalyst is easier and reusability studies shows that the catalyst can be reused to remove the traces of heavy metals with slight reduction in efficiency.

Preparation and Properties of Lauryl Alcohol-Caprylic Acid Eutectics/Activated Charcoal Composites as Shape-stabilized Phase Change Materials for Cold Energy Storage

A novel form-stable composite phase change materials for cold energy storage were prepared using physical blending adsorption method. In the shape-stabilized composites, lauryl alcohol (LA) and caprylic acid (CA) were employed as phase change materials, which were blended together at specific mass ratio based on theoretical calculations. Activated charcoal (AC) was selected as supporting material due to its advantages like large specific surface area and high thermal conductivity. The composites were characterized by field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectrometer (FT-IR), differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). The results of FE-SEM and FT-IR displayed that the eutectics of LA and CA was well absorbed and dispersed homogeneously into the porous network structure of the AC and the melted eutectics was not easy to leak from the reticular structure. Moreover, there was only physical absorption between the eutectic mixture and AC. The results of DSC and TGA indicated that phase change temperature and latent heat of the prepared composites increased with the increase of the binary eutectics mass ratio and AC can enhance the thermal stability of composites. The composites with the mass ratio 60% of the eutectics melted at – 0.21 ℃ with a latent heat enthalpy of 28.08 J/g and solidified at – 2.33 ℃ with a latent solidification enthalpy of 29.70 J/g. The prepared composites will contribute to cold energy storage of low temperature range.

Preparation and in vitro characterization of monoclonal antibody ranibizumab conjugated magnetic nanoparticles for ocular drug delivery

Gold coated magnetite nanoparticles were prepared and coated with ranibizumab as an ocular drug delivery system. The surface morphologies of the nanoparticles were determined by Scanning Electron Microscopy (SEM). The size and surface charge were determined by using the dynamic light scattering (DLS) technique. Crystallographic properties of the gold coated Fe3O4 nanoparticles were recorded on X-ray diffractometer (XRD) the XRD pattern of nanoparticlees were shown to have uniqe Fe3O4 and gold peaks. Conjugation of ranibizumab onto nanoparticles was achieved using the physical adsorption method. The amount of ranibizumab on the surface of the nanoparticles was determined by thermogravimetric analysis (TGA). In the in vitro release studies performed using UV spectroscopy; it was found that almost 60% of antibodies were released within the first 30 minutes. Antibody activity after release studies was also proved with ELISA. Non-toxicity of gold coated Fe3O4 particles were proved with MTT. Results of the studies, showed that the antibody conjugated magnetic nanoparticle system could be a potential treatment system for ocular diseases.

Development of Optimized Strategies for Growth Factor Incorporation onto Electrospun Fibrous Scaffolds To Promote Prolonged Release.

Growth factor incorporation in biomedical constructs for their local delivery enables specific pharmacological effects such as the induction of cell growth and differentiation. This has enabled a promising way to improve the tissue regeneration process. However, it remains challenging to identify an appropriate approach that provides effective growth factor loading into biomedical constructs with their following release kinetics in a prolonged manner. In the present work, we performed a systematic study, which explores the optimal strategy of growth factor incorporation into sub-micrometric-sized CaCO3 core-shell particles (CSPs) and hollow silica particles (SiPs). These carriers were immobilized onto the surface of the polymer scaffolds based on polyhydroxybutyrate (PHB) with and without reduced graphene oxide (rGO) in its structure to examine the functionality of incorporated growth factors. Bone morphogenetic protein-2 (BMP-2) and ErythroPOietin (EPO) as growth factor models were included into CSPs and SiPs using different entrapping strategies, namely, physical adsorption, coprecipitation technique, and freezing-induced loading method. It was shown that the loading efficiency, release characteristics, and bioactivity of incorporated growth factors strongly depend on the chosen strategy of their incorporation into delivery systems. Overall, we demonstrated that the combination of scaffolds with drug delivery systems containing growth factors has great potential in the field of tissue regeneration compared with individual scaffolds.

Albumin self-modified liposomes for hepatic fibrosis therapy via SPARC-dependent pathways.

Activated hepatic stellate cells (HSCs) have a central role in the progression of liver fibrosis and express a large amount of secreted protein, acidic and rich in cysteine (SPARC), a specific protein-binding protein. In this study, we reported the preparation and evaluation of naringenin (Nar) -loaded albumin self-modified liposomes (NaAlLs), which delivered Nar, a specific Smad3 inhibitor that blocked the TGF-β/Smad3 signaling pathway and played an anti-fibrosis role. After a series of characterization, it was found that NaAlLs had favorable dispersion (PDI<0.15) with an average particle size of about 120nm and high entrapment efficiency (>85%), albumin coated the surface of liposomes or embedded in phospholipid bilayer by interaction with the encapsulated naringenin and phospholipid molecules during the preparation of liposomes. The amount of albumin modified to the surface of NaAlLs by this method is not only more than that of the physical adsorption method, but also the binding force between albumin and liposomes is stronger. The albumin modified to the surface of NaAlLs greatly reduced the aggregation of liposomes and drug leakage and increased the stability of liposomes. More importantly, the uptake of NaAlLs by activated HSCs was 1.5 times higher than that of Nar-loaded liposomes (NaLs), suggesting that NaAlLs specifically increased targeting of activated HSCs via albumin and SPARC-dependent pathways. As expected, NaAlLs was more effective in improving liver fibrosis than the NaLs or the inclusion complex solution of Nar and Hydroxypropyl-β-cyclodextrin (NaICS). The results suggested that NaAlLs was a promising drug delivery system, which could target drug delivery to activated HSC for the treatment of liver fibrosis.

Improved Performance of Electrochemically Synthesized Polypyrrole Nanofiber Array-Based Amperometric Glucose Biosensor via Crosslinking Technique.

Herein, we report a novel high sensitivity enzymatic template free glucose biosensor in which enzymes have been immobilized via crosslinking over electropolymerized Polypyrrole nanofiber array (PNA). The nanostructured PPy film was electropolymerized over a Pt-coated glass substrate by the potentiostatic deposition method. Further, the enzyme (GOx) was immobilized over the as-prepared PNA electrode utilizing physical adsorption and crosslinking immobilization method, and the fabricated biosensors were analyzed using amperometric transduction method. The performance of both the types of the biosensor was compared, and further investigations demonstrated the improvement in glucose biosensor response for the electrode utilizing crosslinked GOx. The response time of the prepared biosensor was significantly improved for crosslinked GOx along with nearly six times augmentation in the sensitivity for the same. Among two types of biosensors, the crosslinked electrode based biosensor has shown a high sensitivity of 25.9 mA-cm-2-M-1 and an improved response time of ~30 s with a reasonable linear range of 0.1-2.6 mM which has been reported for the first time via template free electrochemical synthesis approach. The observed results have shown the significant effect of the enzyme immobilization technique on the performance of electrochemical enzymatic glucose biosensor.

Multiwalled carbon nanotubes bound beta-galactosidase: It's activity, stability and reusability.

Carbon nanotubes (CNTs) based biosensors are recognized to be a next generation building block for ultrasensitive and fast biosensing systems. This article starting with a brief history on CNTs provides an overview on the recent expansion of research in the field of CNT-based biosensors. This is followed by the discussion on structure and properties related to CNTs. Furthermore, the basic and some newly developed synthetic methods of CNTs are summarized. In this chapter, we used polyaniline cobalt multiwalled CNTs to immobilize β-galactosidase, by adopting both noncovalent and covalent strategies. Herein, the methodologies of both techniques have been discussed in detail. The η (effectiveness factor) values for nanocomposite bound β-galactosidase by physical adsorption and covalent method were calculated to be 0.93 and 0.97, respectively. The covalently bound β-galactosidase retained 92% activity even after its 10th successive reuse as compared to the adsorbed enzyme which exhibited only 74% of its initial activity. CNT armored enzymes demonstrated remarkably high catalytic stability at both sides of temperature and pH-optima along with easy recovery from the reaction medium which can be utilized in various biotechnological applications. Lastly, the scientific and technological challenges in the field are discussed at the end of this chapter.

Development of a poly(vinyl alcohol)/lysine electrospun membrane-based drug delivery system for improved skin regeneration.

Nanofiber-based wound dressings are currently being explored as delivery systems of different biomolecules for avoiding skin infections as well as improve/accelerate the healing process. In the present work, a nanofibrous membrane composed of poly(vinyl alcohol) (PVA) and lysine (Lys) was produced by using the electrospinning technique. Further, anti-inflammatory (ibuprofen (IBP)) and antibacterial (lavender oil (LO)) agents were incorporated within the electrospun membrane through blend electrospinning and surface physical adsorption methods, respectively. The obtained results demonstrated that the PVA_Lys electrospun membranes incorporating IBP or LO displayed the suitable morphological, mechanical and biological properties for enhancing the wound healing process. Moreover, the controlled and sustained release profile attained for IBP was appropriate for the duration of the wound healing inflammatory phase, whereas the initial burst release of LO is crucial to prevent wound bacterial contamination. Indeed, the PVA_Lys_LO electrospun membranes were able to mediate a strong antibacterial activity against both S. aureus and P. aeruginosa, without compromising human fibroblasts viability. Overall, the gathered data emphasizes the potential of the PVA_Lys electrospun membranes-based drug delivery systems to be used as wound dressings.

Ameliorating the activity and stability of β galactosidase by tailoring potential nanobiocatalyst on functionalized nanographene: Headway to lactose hydrolysis

The ever-growing occurrence of intolerance to dairy products has led to an enormous requirement for immobilization of β galactosidase. In this report, we have shown the immobilization of β galactosidase onto polyaniline doped magnetic graphene (Fe3O4@PANI-GO) nanocomposite. A comparative analysis has been carried out for the integration via physical adsorption and covalent binding methods onto functionalized graphene nanocomposite for analytical application based on lactose reduction. The higher immobilization yield was exhibited in the case of the covalently bound enzyme with ƞ (effectiveness factor) value of 1.49. Characterization of functionalized graphene was studied by scanning and transmission electron microscope, and Fourier-transform infrared spectroscopy studies. Shift of pH optima was observed for covalently bound enzyme from pH 4.5 to 5. The immobilized β galactosidase displayed temperature optima similar to the soluble enzyme at 50 °C. Covalently bound enzyme retained 80% activity even after its 10th successive reuse. The immobilized enzyme displayed higher lactose reduction from milk than the free enzyme. Our conclusions have framed the way for the establishment of graphene-based nanobiosensor to upgrade the quality of milk and its products for easy assimilation by the lactose intolerant patients.

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

Bacillus megaterium 314 strain was able to utilize agricultural and industrial wastes for metallo-protease production. Orange peel and wheat bran were found as the most suitable carbon and nitrogen sources, respectively. Optimized production process enhanced the enzyme production by 5.1-folds. Glass and glass-ceramic with different particle sizes based on mica were used as inorganic carrier. Protease enzyme was immobilized by covalent bonding and physical adsorption methods on nanoparticle supports. Enzyme physically adsorbed on glass ceramic (particle size 0.71–1.0 mm) had the highest residual activity and the highest immobilization yield. Glass-ceramic was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Immobilized enzyme exhibited activation energy (Ea) and deactivation rate constant at 60 °C (kd) about 1.29 and 1.46-times, respectively lower than free enzyme. Moreover, adsorbed enzyme had higher energy for denaturation (Ed), half-life (t1/2), and decimal reduction time (D). The thermodynamic parameters of irreversible thermal denaturation for the protease enzyme indicate that immobilized enzyme had higher enthalpy (ΔH°), free energy (ΔG°), and entropy (ΔS°) than free one. There was a significant improvement in the maximum reaction velocity Vmax (2.5-fold), Michaelis constant Km (1.9-fold), and catalytic efficiency Vmax/Km (4.7-fold) values after immobilization indicating the efficiency and effectiveness of immobilization approach.

Polycarboxylated Dextran as a Multivalent Linker: Synthesis and Target Recognition of the Antibody-Nanoparticle Bioconjugates in PBS and Serum.

Nanoparticles (NPs) functionalized with antibodies on their surface are used in a wide range of research applications. However, the bioconjugation chemistry between the antibodies and the surface of nanoparticles can be very challenging, often accompanied by several undesired effects such as nanoparticle aggregation, antibody denaturation, or poor target recognition of the surface-bound antibodies. Here, we report on a synthesis of fluorescent silica nanoparticle-antibody (NP-Ab) conjugates, in which polycarboxylated dextran is used as the multivalent linker. First, we present a synthetic methodology to prepare polycarboxylated dextrans with molecular weights of 6, 40, and 70 kDa. Second, we used water-soluble, polycarboxylated dextrans as a multivalent spacers/linkers to immobilize antibodies onto fluorescent silica nanoparticles. The prepared NP-Ab conjugates were tested in a direct binding assay format in both phosphate-buffered saline buffer and whole serum to investigate the role of the spacer/linker in the capacity of the NP-Ab to specifically recognize their target in "clean" and also in complex media. We have compared the dextran conjugates with two standards: (a) NP-Ab with antibodies attached on the surface of nanoparticles through the classical physical adsorption method and (b) NP-Ab where an established poly(amidoamine) (PAMAM) dendrimer was used as the linker. Our results showed that the polycarboxylated 6 kDa dextran facilitates antibody immobilization efficiency of nearly 92%. This was directly translated into the improved molecular recognition of the NP-Ab, which was measured by a direct binding assay. The signal-to-noise ratio in buffered solution for the 6 kDa dextran NP-Ab conjugates was 81, nearly 3 times higher than that of PAMAM G4.5 conjugates and 9 times higher than the physically adsorbed NP-Ab sample. In whole serum, the effect of 6 kDa dextran was more hindered due to the formation of protein corona but the signal-to-noise ratio was at least double that of the physically adsorbed NP-Ab conjugates.