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

• Published in: Proteomics (Weinheim) 2008-05, Vol.8 (9), p.1809-1818
• Main Authors: Gokarna, Anisha, Jin, Li-Hua, Hwang, Jun Seok, Cho, Yong-Hoon, Lim, Yong Taik, Chung, Bong Hyun, Youn, Seong Hun, Choi, Dong Sik, Lim, Jung Hyurk
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Biomarkers, Tumor; Cattle; Dip-pen nanolithography; Fundamental and applied biological sciences. Psychology; Gynecology. Andrology. Obstetrics; Humans; Male; Male genital diseases; Medical sciences; Miscellaneous; Nanotechnology - methods; Neoplasm Proteins - chemistry; Nephrology. Urinary tract diseases; Oligonucleotide Array Sequence Analysis; Prostate specific antigen; Prostate-Specific Antigen - chemistry; Prostatic Neoplasms - diagnosis; Prostatic Neoplasms - metabolism; Protein Array Analysis; Protein Interaction Mapping - methods; Protein microarrays; Protein nanoarrays; Proteins; Quantum Dots; Serum Albumin, Bovine - chemistry; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 1615-9853; 1615-9861
• DOI: 10.1002/pmic.200701072

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.