scholarly journals Quenching of Fluorescence Caused by Graphene Oxide as an Immunosensing Platform in a Microwell Plate Format

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 60
Author(s):  
Edwin J. Ortiz-Riaño ◽  
Mariana D. Avila-Huerta ◽  
Diana L. Mancera-Zapata ◽  
Eden Morales-Narváez
Keyword(s):  
Graphene Oxide ◽  
Prostate Specific Antigen ◽  
Electrostatic Interactions ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Human Igg ◽  
Surface Modified ◽  
Microwell Plate ◽  
Oxide Adhesion ◽  
Positively Charged

Immunoassays are, at present, an important tool for diagnostics, drug development, and environmental monitoring. However, most immunoassays involve procedures that require many elements for their development. We introduce a novel biosensing platform based on fluorescence quenching caused by graphene oxide (GO) for the detection of Human-IgG and Prostate-Specific Antigen (PSA). We employ a single antibody for the capture and detection processes, avoiding washing steps. FITC fluorophore was conjugated with antibodies for H-IgG detection, whereas quantum dots were conjugated with antibodies for PSA detection. The simple biosensing platform consists of covering a 96-well microplate (with a polystyrene bottom) with GO. The graphene oxide adhesion is possible by way of electrostatic interactions between the plate surface modified with amino groups (positively charged) and the graphene oxide (negatively charged). This proposal showed an excellent response for the detection of Human-IgG, with acceptable precision (from 0.27% to 5%). The limit of detection reached for H-IgG was 3.35 ng mL-1. In the same manner, for PSA detection, the limit of detection reached was 0.02 ng mL-1 and the precision range was from 0.7% to 15.2%. Furthermore, this biosensing platform was demonstrated to operate with real samples of human urine doped with different concentrations of prostate-specific antigen.

scholarly journals Benign Prostate-specific Antigen (BPSA) in Serum Is Increased in Benign Prostate Disease

2003 ◽  
Vol 49 (2) ◽  
pp. 253-259 ◽  
Author(s):  
Harry J Linton ◽  
Leonard S Marks ◽  
Lisa S Millar ◽  
Christine L Knott ◽  
Harry G Rittenhouse ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Clinical Information ◽  
High Specificity ◽  
Wide Distribution ◽  
Cross Reactivity ◽  
Free Psa ◽  
Control Serum ◽  
Benign Prostate

Abstract Background: BPSA is a “benign” form of free prostate-specific antigen (PSA) that is increased in prostate transition zone tissues of men with pathologic benign prostatic hyperplasia (BPH). We developed an immunoassay to determine the concentration of BPSA in the serum of men with BPH. Methods: The BPSA antigen was purified by HPLC, and murine monoclonal antibodies were prepared by standard methods. A fluorogenic ELISA was developed with high specificity for BPSA and no cross-reactivity with other forms of PSA. Results: The BPSA immunoassay had a lower limit of detection of 6 ng/L and a cross-reactivity of <1% with all other clipped and nonclipped forms of PSA. The BPSA antibody was specific for the internal Lys182 cleavage site that characterizes BPSA. Biopsy-negative men with a median total PSA of 4.8 μg/L had a median of 0.22 μg/L BPSA, representing 25% of the free PSA in serum. BPSA ranged from 0% to 60% of the free PSA in serum. BPSA in a cohort of cancer serum also comprised 25% of the free PSA. Control serum from women or men without increased PSA had nondetectable BPSA. Conclusions: BPSA is a significant percentage of the free PSA in BPH serum but not in control serum. The presence of prostate cancer does not alter the relative proportions of BPSA in sera with <10 μg/L PSA. BPSA has a wide distribution of concentrations in the serum and may provide clinical information for the study of men with BPH.

A graphene oxide-peptide fluorescence sensor for proteolytically active prostate-specific antigen

2012 ◽  
Vol 8 (5) ◽  
pp. 1441 ◽  
Author(s):  
Tingting Feng ◽  
Duan Feng ◽  
Wen Shi ◽  
Xiaohua Li ◽  
Huimin Ma
Keyword(s):  
Graphene Oxide ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Fluorescence Sensor

Effect of Surface Modified Quartz Crystal Microbalance (QCM) on Detection Sensitivity for Prostate Specific Antigen (PSA)

2021 ◽  
Vol 222 (1) ◽  
pp. 93-101
Author(s):  
Thita Sonklin ◽  
Dhananjaya Munthala ◽  
Sanong Suksaweang ◽  
Pattanaphong Janphuang ◽  
Soodkhet Pojprapai
Keyword(s):  
Prostate Specific Antigen ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Specific Antigen ◽  
Detection Sensitivity ◽  
Surface Modified ◽  
Effect Of Surface

Variance function as basis for assessment of test performance: methodological studies with two assays of prostate-specific antigen

1994 ◽  
Vol 40 (11) ◽  
pp. 2046-2052 ◽  
Author(s):  
E Hänseler ◽  
B Keller ◽  
H Keller
Keyword(s):  
Normal Distribution ◽  
Prostate Specific Antigen ◽  
Test Performance ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
Variance Function ◽  
Analytical Performance ◽  
Analytical Sensitivity ◽  
Critical Limit ◽  
Methodological Studies

Abstract We evaluated the usefulness of a recently described procedure to assess the analytical performance of an assay. To demonstrate the advantages of this approach, we compared the performance of two analytical systems for determining prostate-specific antigen (PSA). Triplicate measurements of PSA with the IMx (Abbott) and the ACS 180 (Ciba Corning) were used to calculate the variance function. This function was the basis for the derivation of the critical limit (LC), the limit of detection (LD), the power of definition (PD), and the lower limit of the quantification interval. The standard deviation of the blank was extrapolated by means of the variance function. LC was calculated as the concentration at which the normal distribution of the blank intersects an adjacent normal distribution (with a defined overlap, e.g., 5%). The mean of the adjacent normal distribution represents the LD. The PD is a new mathematical approach to describe the analytical sensitivity of an assay in different ranges of the quantification interval. The procedure is statistically well defined and allows one to obtain the data on the test performance directly from patients' samples, without artificial zero controls. Therefore, use of the variance function could be a general model for the assessment of the analytical performance of an assay.

scholarly journals Development of an Ultrasensitive Immunoassay for Human Glandular Kallikrein with No Cross-Reactivity from Prostate-specific Antigen

1999 ◽  
Vol 45 (6) ◽  
pp. 790-799 ◽  
Author(s):  
Margot H Black ◽  
Angeliki Magklara ◽  
Christina V Obiezu ◽  
Dimitrios N Melegos ◽  
Eleftherios P Diamandis
Keyword(s):  
Detection Limit ◽  
Prostate Specific Antigen ◽  
Seminal Plasma ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Specific Antigen ◽  
Cross Reactivity ◽  
Free Form ◽  
Glandular Kallikrein ◽  
Healthy Males

Abstract Background: Studies demonstrating that human glandular kallikrein (hK2) is increased in prostate cancer patients have prompted speculation that this marker may of use in addition to prostate-specific antigen (PSA). Methods: An ultrasensitive hK2 sandwich immunoassay was developed, and its detection limit, cross-reactivity, analytical recovery, precision, and linearity of dilution were evaluated. hK2 was measured in seminal plasma and sera from healthy males, females, and prostatectomized patients. Results: Our assay has an excellent detection limit (6 ng/L) and precision (>90%). Recovery studies indicated that hK2 binds to serum protease inhibitors. All sera from healthy males had measurable hK2 concentrations (median, 402 ng/L). Almost all female sera had undetectable hK2. Serum hK2 and PSA in males correlated positively (r = 0.44), but hK2 was present at concentrations ∼2.5-fold lower than PSA. The PSA/hK2 ratio in male sera was 0.1–34, with a median of 2.6. In seminal plasma, this ratio was 100–500. More than 94% of immunoreactive hK2 in serum was in the free form (∼30 kDa); traces of hK2 complexed to α1-antichymotrypsin were present. Conclusions: The limit of detection of the method for hK2 measurement described here (∼20-fold lower than any other reported assay for hK2) allows the generation of new clinical information. When combined with a previously described method for PSA measurement that has no cross-reactivity from hK2, this methods allows the relative proportions of hK2 and PSA in biological fluids to be measured.

scholarly journals Improved reverse transcriptase–polymerase chain reaction protocol with exogenous internal competitive control for prostate-specific antigen mRNA in blood and bone marrow

1997 ◽  
Vol 43 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Eva Corey ◽  
Edward W Arfman ◽  
Alvin Y Liu ◽  
Robert L Vessella
Keyword(s):  
Prostate Cancer ◽  
Bone Marrow ◽  
Reverse Transcriptase ◽  
Prostate Specific Antigen ◽  
Mononuclear Cells ◽  
Limit Of Detection ◽  
Specific Antigen ◽  
High Specificity ◽  
Significant Advance ◽  
Peripheral Blood Mononuclear

Abstract The possibility of improving diagnosis of micrometastases from prostate cancer by further enhancing the detection of prostate-specific antigen-producing cells in circulation is being evaluated. We have developed a reverse transcriptase-PCR protocol with the desirable characteristics of low limit of detection, high specificity, reproducibility of response, and ease of performance. Among the procedural alterations that have contributed to these improvements are longer PCR primers, a two-step amplification cycle, and hot-start PCR. We have lowered the limit of detection to one LNCaP prostate-cancer cell in 108 peripheral blood mononuclear cells, and samples of blood and bone marrow from healthy donors have yielded no false positives. Because PCR procedures frequently exhibit tube-to-tube variability, we have incorporated a set of internal and external controls into the protocol—a significant advance in assuring assay reliability.

Sign in / Sign up

Export Citation Format

Share Document