Quantum dot‐based protein micro‐ and nanoarrays for detection of prostate cancer biomarkers

Abstract

In this article, we demonstrate the fabrication and detection of cancer protein biochips consisting of micro- and nanoarrays whereby pegylated quantum dots (QDs) conjugated to antibodies (Abs) of prostate specific antigens (PSA) were used for the detection of clinical biomarkers such as PSA. BSA which acts as an efficient blocking layer in microarrays, tends to show an interaction with QDs. In view of this fact, we investigated two series of samples which were fabricated in the presence and absence of BSA blocking layer. Variation in the incubation time required for the antigen-antibody interaction to take place, different proteins as controls and the effect of bare QDs on these microarrays, were the three main parameters which were studied in these two series. Samples fabricated in the absence of BSA blocking layer exhibited an extremely high specificity in the detection of cancer proteins and were also marked by negligible nonspecific binding effects of QDs, in stark contrast to the samples fabricated using BSA as a blocking layer. Fabrication of nanoarrays of QD-conjugated PSA Abs having a spot size of nearly 900 nm has also been demonstrated. Thus, we show the potential offered by QDs in in vitro analysis of cancer biomarker imaging.

Detection of Cancer Biomarkers With Nanotechnology

“…The past decade has witnessed a surge of applications of QDs in various fields of biomedical sciences, especially in vivo molecular imaging. In one work, QD-conjugated Science Publications AJBB protein micro-and nanoarrays were fabricated and used for the detection of PSA (Gokarna et al, 2008). Results supported that QD-protein conjugated hybrid structures in micro-and nanoarrays showed usefulness for cancer biomarker detection, wherein QDs play a role in the imaging and screening of different types of cancer.…”

Nanotechniques in proteomics: Current status, promises and challenges

“…Nanotechniques offer several advantages over conventional approaches such as miniaturization of assays, real-time multiplexed analysis, low sample and reagent consumption, very high sensitivity and quicker assaying, to name a few. Several nanotechniques such as carbon nanotubes and nanowires Okuno et al, 2007), quantum dots (Gao et al, 2004;Gokarna et al, 2008), gold nanoparticles (Boisselier and Astruc, 2009) and silicon nanowire field effect transistors (Zheng et al, 2005;Lee et al, 2009a) are increasingly being used for proteomic applications like biomarker detection, immunoassays, label-free detection and protein-protein interaction studies (Table 1). Merging microfluidics with protein microarrays (Situma et al, 2006;Lee et al, 2009a) has successfully eliminated many shortcomings of conventional arrays such as higher sample volume, prolonged incubation time and hybridization speeds.…”

Die Anwendung von Viren in Chemo‐ und Biosensoren

“…In den vergangenen zwanzig Jahren sind Sensoren, und besonders Biosensoren, unentbehrlich geworden. Sie ermöglichen den Nachweis so verschiedener Analyte wie Explosivstoffe, [5,6] Proteine, [7,8] DNA, [9,10] Krebsmarker, [11,12] Bakterien, [13,14] Viren [15,16] und Toxine [17,18] in Bereichen wie Nahrungsmittelindustrie, Umweltüberwachung, klinischer Diagnostik oder Bioterrorismus-Bekämpfung. [3,19,20] Je nach Art des Signalwandlers lassen sich die Biosensoren als optisch, thermometrisch, piezoelektrisch, magnetisch, mikromechanisch oder elektrochemisch einstufen.…”