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Application of paper-supported printed gold electrodes for impedimetric immunosensor development.

Ihalainen P, Majumdar H, Viitala T, Törngren B, Närjeoja T, Määttänen A, Sarfraz J, Härmä H, Yliperttula M, Österbacka R, Peltonen J - Biosensors (Basel) (2012)

Bottom Line: In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates.We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique.The article provides a possible biosensor development scheme, where-(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth-all are coupled together to form a test-structure for a recyclable and inexpensive point-of-care diagnostic platform.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence for Functional Materials and Laboratory of Physical Chemistry, Department of Natural Sciences, Åbo Akademi University, Turku, Finland; E-Mails: bjorn.torngren@abo.fi (B.T.); anni.maattanen@abo.fi (A.M.); jawad.sarfraz@abo.fi (J.S.); jouko.peltonen@abo.fi (J.P.).

ABSTRACT
In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates. We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique. The formation process is also supplemented and verified using conventional surface plasmon resonance (SPR) measurements and surface sensitive characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The article provides a possible biosensor development scheme, where-(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth-all are coupled together to form a test-structure for a recyclable and inexpensive point-of-care diagnostic platform.

No MeSH data available.


Capacitance as a function of frequency after each immobilized layer.
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biosensors-03-00001-f007: Capacitance as a function of frequency after each immobilized layer.

Mentions: Following the MBP thiol coverage, the subsequent streptavidin, bio-CRP antigen and anti-CRP antibody layers were consecutively grown on the gold electrodes, as described before. The impedance spectroscopy measurement was done following the formation of each of these layers. Figure 7 shows the systematic variation of the real capacitance for the growth of each successive layer. There is a clear capacitance variation observed in the frequency range of 1 Hz–1kHz. The increase in capacitance cannot be explained using any simple model of equivalent circuit due to the complex nature of the various layers and their interfaces. If we consider capacitance from the double-layers from each interface to add up to a simple capacitive series, then a simple calculation shows that the capacitance for each consecutive layer should decrease the capacitance, not increase it, as seen in Figure 7. The complex nature of the structure would require detailed analysis of the equivalent circuit, which is beyond the scope of the article. The important conclusion is that the impedance measurements show a systematic variation of real capacitance for each consecutive layer growth. This enables the use of the electrical (impedimetric) method for detecting analytes with hand-held, point-of-care diagnostic devices.


Application of paper-supported printed gold electrodes for impedimetric immunosensor development.

Ihalainen P, Majumdar H, Viitala T, Törngren B, Närjeoja T, Määttänen A, Sarfraz J, Härmä H, Yliperttula M, Österbacka R, Peltonen J - Biosensors (Basel) (2012)

Capacitance as a function of frequency after each immobilized layer.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263588&req=5

biosensors-03-00001-f007: Capacitance as a function of frequency after each immobilized layer.
Mentions: Following the MBP thiol coverage, the subsequent streptavidin, bio-CRP antigen and anti-CRP antibody layers were consecutively grown on the gold electrodes, as described before. The impedance spectroscopy measurement was done following the formation of each of these layers. Figure 7 shows the systematic variation of the real capacitance for the growth of each successive layer. There is a clear capacitance variation observed in the frequency range of 1 Hz–1kHz. The increase in capacitance cannot be explained using any simple model of equivalent circuit due to the complex nature of the various layers and their interfaces. If we consider capacitance from the double-layers from each interface to add up to a simple capacitive series, then a simple calculation shows that the capacitance for each consecutive layer should decrease the capacitance, not increase it, as seen in Figure 7. The complex nature of the structure would require detailed analysis of the equivalent circuit, which is beyond the scope of the article. The important conclusion is that the impedance measurements show a systematic variation of real capacitance for each consecutive layer growth. This enables the use of the electrical (impedimetric) method for detecting analytes with hand-held, point-of-care diagnostic devices.

Bottom Line: In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates.We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique.The article provides a possible biosensor development scheme, where-(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth-all are coupled together to form a test-structure for a recyclable and inexpensive point-of-care diagnostic platform.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence for Functional Materials and Laboratory of Physical Chemistry, Department of Natural Sciences, Åbo Akademi University, Turku, Finland; E-Mails: bjorn.torngren@abo.fi (B.T.); anni.maattanen@abo.fi (A.M.); jawad.sarfraz@abo.fi (J.S.); jouko.peltonen@abo.fi (J.P.).

ABSTRACT
In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRP antibody are grown on printed gold electrodes on disposable paper-substrates. We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique. The formation process is also supplemented and verified using conventional surface plasmon resonance (SPR) measurements and surface sensitive characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The article provides a possible biosensor development scheme, where-(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth-all are coupled together to form a test-structure for a recyclable and inexpensive point-of-care diagnostic platform.

No MeSH data available.