cdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation icp-MS as a versatile tool for protein detection

The molecularly imprinted polymer ( MIP ) technology is currently experiencing a rapid development due to the limitations of natural recognition elements such antibodies or aptamers.*

However, neither MIP strategies are limitless. Therefore, the combination of these powerful tools in a specific immunoassay may bring highly selective approach.*
In their article “cdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation icp-MS as a versatile tool for protein detection” Tereza Vaneckova, Jaroslava Bezdekova, Michaela Tvrdonova, Marcela Vlcnovska, Veronika Novotna, Jan Neuman, Aneta Stossova, Viktor  Kanicky, Vojtech Adam, Marketa Vaculovicova and  Tomas Vaculovic introduce a MIP-based pseudo-immunoassay using NP-labelled antibody recognition and couple it with the sensitive detection technique  laser ablation inductively coupled plasma mass spectrometry ( LA-ICP-MS ).*

Two approaches of specific recognition were tested.
The first one was based on the immunolabelling of the analyte captured by the MIP layer.
The second approach involved immunolabelling of the analyte as a first step and the resulting QD-AB-AG complex was captured by MIP and further analyzed.
The double-selective approach comprising of the specific immunolabelling reaction combined with isolation by MIP together with the LA-ICP-MS detection represents a viable approach of the IgG detection from a complex sample (LOD 4.2 μg and 1.6 μg, respectively) available for many exciting applications.
Considering the overall time of the LA-ICP-MS analysis not exceeding 23 s (scan speed of 2000 μm/s), LA-ICP-MS is a promising technology to be used in future in conjunction with MIP technology.*

The sample surface was analyzed using SEM with integrated AFM. Correlative Probe and Electron Microscopy (CPEM)48 was used for the surface analysis allowing simultaneous acquisition of SEM and AFM images at the same place in the same coordinate system. The SEM contrast is sensitive to the sample composition, while the AFM provides real surface topography. The accelerating voltage of 5 kV, beam current of 13 pA and SE detector was used for SEM imaging.*
NANOSENSORS self-sensing self-actuating Akiyama probes in tapping mode were used for the AFM measurement.


Figure 3 c from: «CdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation ICP-MS as a versatile tool for protein detection» by Tereza Vaneckova et al.
(C) Correlative Probe and Electron Microscopy (CPEM) imaging of MIP layer with imprinted QD-AB conjugate. 1 – SEM image, 2 – AFM image of the same area and sample in the same coordinate system. 3 – profile of a well formed due to the imprinting process.
In Fig. 3C, the surface visualization obtained by Correlative Probe and Electron Microscopy (CPEM) is shown. SEM image (1) and AFM image (2) were obtained simultaneously from the same region of the sample. Mainly two regions of the surface are of our interest (red and blue circle). Even though SEM image shows similar contrast of both regions, AFM imaging clearly confirms differences between the flat surface (blue circle) and wells formed due to the imprinting process (red circle). Profile of one of the wells is shown in (3). *
NANOSENSORS self-sensing and self-actuating Akiyama-probe AFM probe
NANOSENSORS self-sensing and self-actuating Akiyama-probe

*Tereza Vaneckova, Jaroslava Bezdekova, Michaela Tvrdonova, Marcela Vlcnovska, Veronika Novotna, Jan Neuman, Aneta Stossova, Viktor  Kanicky, Vojtech Adam, Marketa Vaculovicova, Tomas Vaculovic
cdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation icp-MS as a versatile tool for protein detection
nature, Scientific Reports, (2019) 9:11840
DOI: https://doi.org/10.1038/s41598-019-48290-2

Please follow this external link to read the full article: https://rdcu.be/bXosX

Open Access The article “CdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation ICP-MS as a versatile tool for protein detection” by Tereza Vaneckova, Jaroslava Bezdekova, Michaela Tvrdonova, Marcela Vlcnovska, Veronika Novotna, Jan Neuman, Aneta Stossova, Viktor  Kanicky, Vojtech Adam, Marketa Vaculovicova and Tomas Vaculovic is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Video on NANOSENSORS™ Membrane-type Surface-stress Sensors (MSS) for olfactory sensing passes 1000 views mark

The video on NANOSENSORS™ Membrane-type Surface-stress Sensors (MSS) for olfactory sensing has just passed the 1000 views mark. Thank you all for watching.

The NANOSENSORS Membrane-type Surface-stress Sensor – MSS is a non-packaged MEMS sensor, a silicon membrane platform supported with four beams on which piezoresistors are embedded. It is mainly dedicated to R&D in the areas of olfactory sensing and electronic noses.

There are currently two major applications for this type of sensor:

  • the MSS has a great potential as a core component for electronic (artificial) nose systems / olfactory sensing systems utilized in e.g., medical, food, environment, safety and security fields.
  • the MSS can also be used for assessment of various materials like organic conductors, magnetic and superconductor materials in torque magnetometry.

To find out more please have a look at the video or at the NANOSENSORS™ MSS webpage.

Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages

Caffeine is widely present in food and drinks, such as teas and coffees, being also part of some currently commercialized medicines, but despite its enhancement on several functions of human body, its exceeding use can promote many health problems.*

The paper “Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages” by Leonardo de A. Furtado, Mariana C. de O. Gonçalves, Carlos V. M. Inocêncio, Edilson M. Pinto, Daniela de L. Martins and Felipe S. Semaan presents a new method for the determination of caffeine through voltammetry using the square wave technique.*

In order to develop new fast approaches for the caffeine sensing, graphite-epoxy composite electrodes (GECE) were used as substrate, being modified by different diazonium salts, synthetized as their tetraflouroborate salts.
The paper by Leonardo de A. Furtado et al. presents the modification procedure, the study of pH used for buffer solution’s choice, and an electrochemical impedance spectroscopy (EIS) study of all modifications in presence and absence of the analyte, as well, analytical comparison with bare and modified electrodes for caffeine determination.*

Atomic Force Microscopy images were measured to evaluate the surface topography and roughness, before and after the modification. The AFM images showed a decrease in the surface roughness after modification of the electrodes with diazonium salts. Based on this data, it is possible to infer that the modification made a more homogeneous surface compared with the bare electrode.* NANOSENSORS™ PointProbe® Plus PPP-NCLR AFM probes were used.



Figure 5 from “Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages” by Leonardo de A. Furtado et al.:
Surface topography via AFM of (a) bare electrode and (b) electrode modified with 4-benzenesulfonic acid.

*Leonardo de A. Furtado, Mariana C. de O. Gonçalves, Carlos V. M. Inocêncio, Edilson M. Pinto, Daniela de L. Martins and Felipe S. Semaan
Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages
Journal of Analytical Methods in Chemistry, Volume 2019, Article ID 8596484, 11 pages
DOI: https://doi.org/10.1155/2019/8596484

Please follow this external link to read the full article: https://www.hindawi.com/journals/jamc/2019/8596484/

Open Access: The article “Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages” by Leonardo de A. Furtado, Mariana C. de O. Gonçalves, Carlos V. M. Inocêncio, Edilson M. Pinto, Daniela de L. Martins and Felipe S. Semaan which is cited above is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.