Limits...
Single step nanoplasmonic immunoassay for the measurement of protein biomarkers.

Prabhulkar S, de la Zerda A, Paranjape A, Awdeh RM - Biosensors (Basel) (2013)

Bottom Line: This nanoplasmonic immunoassay can act as a simple, selective, sensitive strategy for effective disease diagnosis.It offers advantages such as wide detection range, increased speed of analysis (due to fewer incubation/washing steps), and no label development as compared to traditional immunoassay techniques.Our future goal is to incorporate this detection strategy onto a microfluidic platform to be used as a point-of-care diagnostic tool.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Miami-Bascom Palmer Eye Institute, Miami, FL 33136, USA; E-Mails: sprabhulkar@med.miami.edu (S.P.); asparanjape@gmail.com (A.P.).

ABSTRACT
A nanoplasmonic biosensor for highly-sensitive, single-step detection of protein biomarkers is presented. The principle is based on the utilization of the optical scattering properties of gold nanorods (GNRs) conjugated to bio-recognition molecules. The nanoplasmonic properties of the GNRs were utilized to detect proteins using near-infrared light interferometry. We show that the antibody-conjugated GNRs can specifically bind to our model analyte, Glucose Transporter-1 (Glut-1). The signal intensity of back-scattered light from the GNRs bound after incubation, correlated well to the Glut-1 concentration as per the calibration curve. The detection range using this nanoplasmonic immunoassay ranges from 10 ng/mL to 1 ug/mL for Glut-1. The minimal detectable concentration based on the lowest discernable concentration from zero is 10 ng/mL. This nanoplasmonic immunoassay can act as a simple, selective, sensitive strategy for effective disease diagnosis. It offers advantages such as wide detection range, increased speed of analysis (due to fewer incubation/washing steps), and no label development as compared to traditional immunoassay techniques. Our future goal is to incorporate this detection strategy onto a microfluidic platform to be used as a point-of-care diagnostic tool.

No MeSH data available.


Specificity study conducted using human vascular endothelial growth factor (VEGF) and BSA as competitive analytes for anti-Glut-1 tagged gold nanorods.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263591&req=5

biosensors-03-00077-f004: Specificity study conducted using human vascular endothelial growth factor (VEGF) and BSA as competitive analytes for anti-Glut-1 tagged gold nanorods.

Mentions: Specificity is a crucial parameter, which influences the performance of a biosensor in real matrices. We need to prove that the presented sensor responds only to the Glut-1 and anti-Glut-1 immunoreaction and not towards the nonspecific interaction with other proteins. In order to demonstrate the specificity of the biosensor we conducted studies using VEGF and BSA as competitive analytes. Figure 4, shows the average OCT signal intensity (10 replicates were conducted for each data set) measured for Glut-1, VEGF and BSA respectively. The wells containing Glut-1 display the highest OCT signal intensity, which translates to the highest binding efficiency of anti-Glut-1 tagged GNRs. The wells containing VEGF and BSA show a non-significant increment of 12.65 ± 8.3 and 36.35 ± 14.1 respectively in signal intensity as compared to control wells containing PBS buffer. Hence we can conclude that the 353.13 ± 32.1 signal intensity increment measured for the wells containing Glut-1 was caused due the highly selective immunoreactions between Glut-1 and anti-Glut-1 tagged GNRs. In order to study the interference that could be caused by the interference of non-specific proteins in the test sample we tested wells containing combinations of Glut-1 + VEGF, Glut-1 +BSA and Glut-1 + VEGF +BSA such that the combined molarity of the samples was 500 ng/mL. Based on the results shown in Figure 4 we can conclude that the presence of VEGF and BSA did not cause any hindrance towards the binding of GNRs to Glut-1 protein.


Single step nanoplasmonic immunoassay for the measurement of protein biomarkers.

Prabhulkar S, de la Zerda A, Paranjape A, Awdeh RM - Biosensors (Basel) (2013)

Specificity study conducted using human vascular endothelial growth factor (VEGF) and BSA as competitive analytes for anti-Glut-1 tagged gold nanorods.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263591&req=5

biosensors-03-00077-f004: Specificity study conducted using human vascular endothelial growth factor (VEGF) and BSA as competitive analytes for anti-Glut-1 tagged gold nanorods.
Mentions: Specificity is a crucial parameter, which influences the performance of a biosensor in real matrices. We need to prove that the presented sensor responds only to the Glut-1 and anti-Glut-1 immunoreaction and not towards the nonspecific interaction with other proteins. In order to demonstrate the specificity of the biosensor we conducted studies using VEGF and BSA as competitive analytes. Figure 4, shows the average OCT signal intensity (10 replicates were conducted for each data set) measured for Glut-1, VEGF and BSA respectively. The wells containing Glut-1 display the highest OCT signal intensity, which translates to the highest binding efficiency of anti-Glut-1 tagged GNRs. The wells containing VEGF and BSA show a non-significant increment of 12.65 ± 8.3 and 36.35 ± 14.1 respectively in signal intensity as compared to control wells containing PBS buffer. Hence we can conclude that the 353.13 ± 32.1 signal intensity increment measured for the wells containing Glut-1 was caused due the highly selective immunoreactions between Glut-1 and anti-Glut-1 tagged GNRs. In order to study the interference that could be caused by the interference of non-specific proteins in the test sample we tested wells containing combinations of Glut-1 + VEGF, Glut-1 +BSA and Glut-1 + VEGF +BSA such that the combined molarity of the samples was 500 ng/mL. Based on the results shown in Figure 4 we can conclude that the presence of VEGF and BSA did not cause any hindrance towards the binding of GNRs to Glut-1 protein.

Bottom Line: This nanoplasmonic immunoassay can act as a simple, selective, sensitive strategy for effective disease diagnosis.It offers advantages such as wide detection range, increased speed of analysis (due to fewer incubation/washing steps), and no label development as compared to traditional immunoassay techniques.Our future goal is to incorporate this detection strategy onto a microfluidic platform to be used as a point-of-care diagnostic tool.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Miami-Bascom Palmer Eye Institute, Miami, FL 33136, USA; E-Mails: sprabhulkar@med.miami.edu (S.P.); asparanjape@gmail.com (A.P.).

ABSTRACT
A nanoplasmonic biosensor for highly-sensitive, single-step detection of protein biomarkers is presented. The principle is based on the utilization of the optical scattering properties of gold nanorods (GNRs) conjugated to bio-recognition molecules. The nanoplasmonic properties of the GNRs were utilized to detect proteins using near-infrared light interferometry. We show that the antibody-conjugated GNRs can specifically bind to our model analyte, Glucose Transporter-1 (Glut-1). The signal intensity of back-scattered light from the GNRs bound after incubation, correlated well to the Glut-1 concentration as per the calibration curve. The detection range using this nanoplasmonic immunoassay ranges from 10 ng/mL to 1 ug/mL for Glut-1. The minimal detectable concentration based on the lowest discernable concentration from zero is 10 ng/mL. This nanoplasmonic immunoassay can act as a simple, selective, sensitive strategy for effective disease diagnosis. It offers advantages such as wide detection range, increased speed of analysis (due to fewer incubation/washing steps), and no label development as compared to traditional immunoassay techniques. Our future goal is to incorporate this detection strategy onto a microfluidic platform to be used as a point-of-care diagnostic tool.

No MeSH data available.