Oblique-Incidence Reflectivity Difference and Fluorescence Imaging of Oligonucleotide and IgG Protein Microarrays

2003 ◽  
Vol 773 ◽  
Author(s):  
James P. Landry ◽  
X. D. Zhu ◽  
X. W. Guo ◽  
J. P. Gregg
Keyword(s):  
Oblique Incidence ◽  
Protein Microarrays ◽  
Fluorescent Labeling ◽  
Fluorescent Label ◽  
Label Free ◽  
Detection Techniques ◽  
Glass Substrates ◽  
Standard Glass ◽  
Non Destructive ◽  
Microarray Detection

AbstractWe have constructed an oblique-incidence reflectivity difference (OI-RD) microscope for fluorescent label-free imaging of DNA and protein microarrays on standard glass substrates. Using both OI-RD and fluorescence images, we demonstrate a difference in wetting behavior of labeled and unlabeled IgG protein molecules deposited on an aldehyde-derivatized glass surface. The potential of fluorescent labeling agents to influence the properties of proteins highlights the need for label-free microarray detection techniques to supplement existing fluorescence methods. We also present OI-RD images of an oligonucleotide microarray after printing and washing procedures to demonstrate the use of OI-RD for non-destructive monitoring of changes in the optical properties of microarrays during processing.

scholarly journals Label-free detection techniques for protein microarrays: Prospects, merits and challenges

PROTEOMICS ◽  
2009 ◽  
Vol 10 (4) ◽  
pp. 731-748 ◽  
Author(s):  
Sandipan Ray ◽  
Gunjan Mehta ◽  
Sanjeeva Srivastava
Keyword(s):  
Protein Microarrays ◽  
Label Free ◽  
Detection Techniques ◽  
Label Free Detection

Electronic Detection and Quantification of ions in solution using an a-Si:H Field-effect Device

2009 ◽  
Vol 1153 ◽  
Author(s):  
João Costa ◽  
Miguel Fernandes ◽  
Manuela Vieira ◽  
G. Lavareda ◽  
C. N. Carvalho ◽  
...  
Keyword(s):  
Field Effect ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
Reference Electrode ◽  
Industrial Effluents ◽  
Label Free ◽  
Detection Techniques ◽  
Glass Substrates ◽  
Current Voltage ◽  
Semiconductor Transducer

AbstractProgress in microelectronics and semiconductor technology has enable new capabilities in the field of sensor construction, particularly of pH sensors based on field-effect transistors (FETs) as transducers of chemical signal. While crystalline devices present a higher sensitivity, their amorphous counterpart present a much lower fabrication cost, thus enabling the production of cheap disposable sensors for use in the food industry. Interest in biosensors consisting of a semiconductor transducer and a functionalized surface with biomolecule receptors (BioFET) continues to grow as they hold the promise for highly selective, label-free, real-time sensing as an alternative to conventional optical detection techniques. We have been involved in the development of a biosensor where the enzymatic activity of recombinant amidase from Escherichia coli is coupled to a semiconductor transducer for the detection of toxic amides in food and industrial effluents. The devices were fabricated on glass substrates by the PECVD technique in the top gate configuration, where the metallic gate is replaced by an electrolytic solution with an immersed Ag/AgCl reference electrode. Silicon nitride is used as gate dielectric enhancing the sensitivity and passivation layer used to avoid leakage and electrochemical reactions. In this article we report on the semiconductor unit, showing that the sensor displays the desired current-voltage characteristics. In addition we present an electrical model of the device, in agreement with the experimental data, that is sensitive to the pH of the solution.

Label-free detection repeatability of protein microarrays by oblique-incidence reflectivity difference method

2012 ◽  
Vol 55 (12) ◽  
pp. 2347-2350 ◽  
Author(s):  
Jun Dai ◽  
Lin Li ◽  
JingYi Wang ◽  
LiPing He ◽  
HuiBin Lu ◽  
...  
Keyword(s):  
Difference Method ◽  
Oblique Incidence ◽  
Protein Microarrays ◽  
Label Free ◽  
Label Free Detection

scholarly journals Label and Label-Free Detection Techniques for Protein Microarrays

Microarrays ◽  
2015 ◽  
Vol 4 (2) ◽  
pp. 228-244 ◽  
Author(s):  
Amir Syahir ◽  
Kenji Usui ◽  
Kin-ya Tomizaki ◽  
Kotaro Kajikawa ◽  
Hisakazu Mihara
Keyword(s):  
Protein Microarrays ◽  
Label Free ◽  
Detection Techniques ◽  
Label Free Detection

scholarly journals Characterization of Liposomes Using Quantitative Phase Microscopy (QPM)

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 590
Author(s):  
Jennifer Cauzzo ◽  
Nikhil Jayakumar ◽  
Balpreet Singh Ahluwalia ◽  
Azeem Ahmad ◽  
Nataša Škalko-Basnet
Keyword(s):  
Rapid Development ◽  
Fluorescent Labeling ◽  
Label Free ◽  
Batch Mode ◽  
Full Field ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Tracking Ability

The rapid development of nanomedicine and drug delivery systems calls for new and effective characterization techniques that can accurately characterize both the properties and the behavior of nanosystems. Standard methods such as dynamic light scattering (DLS) and fluorescent-based assays present challenges in terms of system’s instability, machine sensitivity, and loss of tracking ability, among others. In this study, we explore some of the downsides of batch-mode analyses and fluorescent labeling, while introducing quantitative phase microscopy (QPM) as a label-free complimentary characterization technique. Liposomes were used as a model nanocarrier for their therapeutic relevance and structural versatility. A successful immobilization of liposomes in a non-dried setup allowed for static imaging conditions in an off-axis phase microscope. Image reconstruction was then performed with a phase-shifting algorithm providing high spatial resolution. Our results show the potential of QPM to localize subdiffraction-limited liposomes, estimate their size, and track their integrity over time. Moreover, QPM full-field-of-view images enable the estimation of a single-particle-based size distribution, providing an alternative to the batch mode approach. QPM thus overcomes some of the drawbacks of the conventional methods, serving as a relevant complimentary technique in the characterization of nanosystems.

scholarly journals Cellular lensing and near infrared fluorescent nanosensor arrays to enable chemical efflux cytometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Soo-Yeon Cho ◽  
Xun Gong ◽  
Volodymyr B. Koman ◽  
Matthias Kuehne ◽  
Sun Jin Moon ◽  
...  
Keyword(s):  
Near Infrared ◽  
Single Cells ◽  
Microfluidic Channel ◽  
Human Monocyte ◽  
Cellular Heterogeneity ◽  
Label Free ◽  
Nanotube Array ◽  
Chemical Cytometry ◽  
Rich Information ◽  
Non Destructive

AbstractNanosensors have proven to be powerful tools to monitor single cells, achieving spatiotemporal precision even at molecular level. However, there has not been way of extending this approach to statistically relevant numbers of living cells. Herein, we design and fabricate nanosensor array in microfluidics that addresses this limitation, creating a Nanosensor Chemical Cytometry (NCC). nIR fluorescent carbon nanotube array is integrated along microfluidic channel through which flowing cells is guided. We can utilize the flowing cell itself as highly informative Gaussian lenses projecting nIR profiles and extract rich information. This unique biophotonic waveguide allows for quantified cross-correlation of biomolecular information with various physical properties and creates label-free chemical cytometer for cellular heterogeneity measurement. As an example, the NCC can profile the immune heterogeneities of human monocyte populations at attomolar sensitivity in completely non-destructive and real-time manner with rate of ~600 cells/hr, highest range demonstrated to date for state-of-the-art chemical cytometry.

Detection of the specific binding on protein microarrays by oblique-incidence reflectivity difference method

2010 ◽  
Vol 12 (9) ◽  
pp. 095301 ◽  
Author(s):  
Heng Lu ◽  
Juan Wen ◽  
Xu Wang ◽  
Kun Yuan ◽  
Wei Li ◽  
...  
Keyword(s):  
Difference Method ◽  
Oblique Incidence ◽  
Specific Binding ◽  
Protein Microarrays
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