Enhancement of antigen–antibody kinetics on nanotextured silicon surfaces in mixed non-flow systems

Rath, Dharitri; Kumar, Satyendra; Panda, Siddhartha

doi:10.1016/j.msec.2012.06.006

Cited by 9 publications

(7 citation statements)

References 37 publications

(53 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 1D, the mixing efficiency of this micromixer reaches 90% when three fluids flow through four convergence−divergence spirals at a flow rate of 100 μL/min. Because the immunoreaction between the target bacteria and the capture/detection antibodies takes certain time, 31 additional four convergence− divergence spirals were established for incubation to allow a sufficient reaction. To further understand the mixing effect, the gray values of the images at the inlet and the outlet were analyzed by ImageJ software.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Jin

Guo

et al. 2021

ACS Sens.

View full text Add to dashboard Cite

In-field screening of foodborne pathogens plays an important role in ensuring food safety. Thus, a microfluidic biosensor was developed for rapid and sensitive detection of Salmonella using manganese dioxide nanoflowers (MnO2 NFs) for amplifying the biological signal, a microfluidic chip with a convergence–divergence spiral micromixer for performing automatic operations, and a smartphone app with a saturation calculation algorithm for processing the image. First, immune magnetic nanoparticles (MNPs), the sample, and immune MnO2 NFs were fully mixed and sufficiently incubated in the spiral micromixer to form MNP–bacteria–MnO2 sandwich complexes, which were magnetically captured in a separation chamber in the microfluidic chip. Then, a 3,3′,5,5′-tetramethylbenzidine (TMB) substrate was injected and catalyzed by a MnO2 NF nanomimetic enzyme on the complexes, resulting in the production of yellow catalysate. Finally, the catalysate was transferred into a detection chamber and its image was measured and processed using the smartphone app to determine the number of bacteria. This biosensor was able to detect Salmonella from 4.4 × 101 to 4.4 × 106 CFU/mL in 45 min with a detection limit of 44 CFU/mL, and has the potential to provide a promising platform for on-site detection of foodborne bacteria.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Jin

Guo

et al. 2021

ACS Sens.

View full text Add to dashboard Cite

show abstract

“…The choice of the values of the parameters used was based on our previous experimental study as well as values reported in the literature for antigen−antibody systems. 16,28 A mixing speed of 500 rpm was chosen based on our previous experiments where the capture of antigens could be enhanced by using different mixing speeds. 2,16 Other mixing speeds could also have been used, but we have considered only one speed as an exemplary case.…”

Section: Dependency Of Capture Efficiency Onmentioning

confidence: 99%

“…16,28 A mixing speed of 500 rpm was chosen based on our previous experiments where the capture of antigens could be enhanced by using different mixing speeds. 2,16 Other mixing speeds could also have been used, but we have considered only one speed as an exemplary case. It can be observed from Figure 9a that for a given radial distance the capture efficiencies decrease with increase in K D .…”

Section: Dependency Of Capture Efficiency Onmentioning

confidence: 99%

Correlation of Capture Efficiency with the Geometry, Transport, and Reaction Parameters in Heterogeneous Immunosensors

Rath

Panda

2016

Langmuir

Self Cite

View full text Add to dashboard Cite

Higher capture efficiency of biomarkers in heterogeneous immunosensors would enable early detection of diseases. Several strategies are used to improve the capture efficiency of these immunosensors including the geometry of the system along with the transport and reaction parameters. Having a prior knowledge of the behavior of the above parameters would facilitate the design of an efficient immunosensor. While the contributions of the transport and reaction parameters toward understanding of the mechanism involved in capture have been well studied in the literature, their effect in combination with the geometry of the sensors has not been explored until now. In this work, we have experimentally demonstrated that the capture efficiency of the antigen-antibody systems is inversely related to the size of the sensor patch. The experimental system was simulated in order to get an in-depth understanding of the mechanism behind the experimental observation. Further, the extent of heterogeneity in the system was analyzed using the Sips isotherm to obtain the heterogeneity index (α) and the reaction rate constant (K(D)) as fitted parameters for a sensor patch of 1.5 mm radius. The experimental kinetic data obtained for the same sensor patch matched reasonably with the simulation results by considering K(D) as the global affinity constant, which indicated that our system can be considered to be homogeneous. Our simulation results associated with the size dependency of the capture efficiency were in agreement with the trends obtained in our experimental observations where an inverse relation was observed owing to the fact that the mass-transfer limitation decreases with the decrease in the size of the sensor patch. The possible underlying mechanism associated with size dependency of capture efficiency was discussed based on the time-dependent radial variation of captured antigens obtained from our simulation results. A study on the parametric variation was further conducted for the nonmixed and mixed systems on the transport (Deff), reaction (K(D)), and geometric parameters (R). Two different correlations were established for the nonmixed and mixed systems between the capture efficiency (f) and a nondimensional number (t(D)/t(R)) consisting of the above-mentioned parameters. Such unified relations will be useful in designing heterogeneous immunosensors and can be extended to microfluidic immunosensors.

show abstract

“…The values of D′ rot were found to be in the range of values of D eff (1 × 10 −9 -1 × 10 −12 m 2 s −1 ) reported earlier. 2,45 …”

Section: Contribution To the Effective Diffusivity (D Eff )mentioning

confidence: 99%

“…1 The investigation of the physicochemical properties of these clinically relevant biomarkers is of great interest to the scientific community for improving the detection limit by enhancing their capture in an immunosensor. 2 The major challenge associated with the detection of these biomarkers is their extremely low concentration levels in the human body. Hence, the development of a fast, accurate, and efficient immunosensor is of great importance.…”

Section: Introductionmentioning

confidence: 99%

Contribution of rotational diffusivity towards the transport of antigens in heterogeneous immunosensors

Rath

Panda

2015

Analyst

Self Cite

View full text Add to dashboard Cite

Higher capture efficiency in heterogeneous immunosensors is desirable for the detection of cancer biomarkers at low concentrations. The process of the capture of these antigens is transport limited since the rates of antigen/antibody reactions are faster. In the case of non-flow systems, diffusive transport has contributions from both translational and rotational phenomena. Since the contribution of the rotational diffusivity is comparatively less explored in the literature, we have studied the same for three antigens – bovine serum albumin (BSA), prostate specific antigen (PSA) and C-reactive proteins (CRP). We quantified the rotational diffusivities using the time resolved fluorescence anisotropy method, and further quantified the contribution of the rotational diffusivities to the overall diffusivity of the antigens, and also studied the effect of the process parameters – temperature and pH of the solution. With an increase in temperature, the rotational diffusivity increased showing Arrhenius dependence while with the variation of pH, it showed a non-monotonic behavior having maxima closer to the isoelectric point of the corresponding antigens. This interesting behavior of the pH values could be attributed to lesser electro-viscous effects when the antigen molecule is neutral around its isoelectric point. The optimization of the pH and temperature for the immunosensors could be utilized to design efficient immunosensors.

show abstract

Enhancement of antigen–antibody kinetics on nanotextured silicon surfaces in mixed non-flow systems

Cited by 9 publications

References 37 publications

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Correlation of Capture Efficiency with the Geometry, Transport, and Reaction Parameters in Heterogeneous Immunosensors

Contribution of rotational diffusivity towards the transport of antigens in heterogeneous immunosensors

Contact Info

Product

Resources

About

Enhancement of antigen–antibody kinetics on nanotextured silicon surfaces in mixed non-flow systems

Cited by 9 publications

References 37 publications

Microfluidic Colorimetric Biosensors Based on MnO2 Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Microfluidic Colorimetric Biosensors Based on MnO2 Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Correlation of Capture Efficiency with the Geometry, Transport, and Reaction Parameters in Heterogeneous Immunosensors

Contribution of rotational diffusivity towards the transport of antigens in heterogeneous immunosensors

Contact Info

Product

Resources

About

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella

Microfluidic Colorimetric Biosensors Based on MnO₂ Nanozymes and Convergence–Divergence Spiral Micromixers for Rapid and Sensitive Detection of Salmonella