Quantification Of Prostate Specific Antigen Research Articles

Quantification of Urinary Exosomal Prostate-Specific Antigen for the Diagnosis of Prostate Cancer Using Clinical Laboratory-Based Techniques: Protocol for a Case-Control Study.

Prostate cancer is the most common cancer in men and represents a major public health problem. The current method for the diagnosis or screening of prostate cancer is invasive and costly. There have been renewed and innovative studies searching for urinary biomarkers to aid in the diagnosis of prostate cancer, especially with technologies based on urinary exosomes. However, technologies based on urine exosomes usually need expensive machines such as an ultracentrifuge and they are difficult to standardize, which hinder their application in clinical laboratories. We have optimized and standardized the isolation of urinary exosomes with the precipitation method. We have found that urinary exosomal prostate-specific antigen (PSA) can be quantified by automatic Elecsys total PSA technique. In this study, our objective is to utilize urinary exosomes from prostate cancer for the development of a test to aid in its diagnosis. Exosomes from the prostate cancer cell line LNCaP was used to set up the technique. To analyze urine samples from patients, the methods include the collection of first-void urine using the Colli-Pee device, the isolation of urine exosomes using the optimized precipitation method, and the quantification of exosomal PSA by Elecsys total PSA. This will be a 2-year study. We will start including patients and controls in the last quarter of 2024. We expect the results to be published in the second quarter of 2027. This is the first study to quantify urinary exosomal PSA using the Elecsys total PSA technique for the diagnosis of prostate cancer. This study emphasizes techniques that are suitable for implementation in clinical laboratories, which will facilitate the application of urinary exosomes to simplify and improve the diagnosis and screening of prostate cancer. PRR1-10.2196/63551.

Graphene-based field-effect transistor biosensor for prostate-specific antigen detection

The development of a graphene-based field-effect transistor (GFET) aptasensor for prostate-specific antigen (PSA) detection. We present the novel use of 1-pyrenebutyric acid N-hydroxysuccinimide ester (PBASE) to functionalize the graphene surface, enabling covalent bonding of amine-functionalized PSA-binding aptamers. Under optimized conditions, the shift of the GFET aptasensor’s Dirac point voltage exhibited a systematic variation with PSA concentrations. The sensor demonstrated a relatively wide linear dynamic range spanning from 100 fM to 100 nM, with a detection limit of 3.5 pM. Importantly, it displayed satisfactory specificity against potential interfering proteins and demonstrated good reproducibility and stability. Furthermore, we successfully applied the proposed method for the quantification of PSA in human serum samples, indicating its potential for bioanalysis and clinical diagnostics. The GFET aptasensor’s potential in medical diagnostics and personalized healthcare, positioning it as a promising tool for rapid and accurate biomarker detection.

Rapid quantification of prostate specific antigen (PSA) from fingerstick (FS) blood.

279 Background: Screening for prostate cancer (PC) reduces PC-specific deaths. African American (AA) individuals have a ~2-fold higher risk of developing and dying from PC and may benefit from screening at a younger age. To increase access to PC screening for high-risk communities, we developed a portable, rapid point of care (POC) PSA test that quantifies PSA from FS blood in 20 minutes. We present preliminary data for our POC test. Methods: We developed a lateral flow immunoassay test strip1 combined with the Cube Reader (Chembio Diagnostics GmbH) to quantify PSA from FS blood. These measurements were compared on the same day with standard venous blood PSA as measured with the Siemens Centaur Chemiluminescent Immunoassay. Following informed consent, 50 µL of FS blood was mixed with 80 µL of buffer (PBS 1X with 1% Tween-20) and loaded onto the test strip. This ratio was found to be effective for adequate sample flow on the test strip. Eligible patients (pts) were undergoing standard of care PSA testing and had a recent PSA <20 ng/mL (to resemble a screening population). Pts with and without PC were included. Colorimetric signal intensities of the Test (T) and Control (C) lines were measured at 20 min with the Cube Reader. A scatter plot and Pearson correlation coefficient between the T/C ratios and the PSA results from venous blood were obtained for a group of 42 preliminary pts. A cohort of 30 pts additionally had 200 µL of FS blood (the minimum sufficient quantity) collected for serum analysis via the Centaur assay. This was done to evaluate for any unexpected variability between laboratory-based capillary and venous PSA results, and to test the feasibility of measuring PSA in the lab with a small volume of blood. Results: In these preliminary results, the 30 pts who had PSA measured from capillary and venous sera via the Centaur assay showed a correlation coefficient of 0.99. In the cohort of 42 pts who had PSA T/C ratios measured with the test strip, the correlation with venous PSA was 0.9. This encompassed a PSA range of 0.3-19.6 ng/mL with one outlier of 179 ng/mL. Based on a preliminary calibration curve from a small sample of 21 pts, the sensitivity and specificity of the POC test to detect a PSA >4 ng/mL was 100% (95% CI: 71.51-100) and 90% (95% CI: 55.50-99.75), respectively, in the 0.3-10 ng/mL detection range. Nineteen percent (8/42) of pts were AA. Conclusions: Serum from capillary and venous blood shows a strong correlation when measured via a standard laboratory assay. In addition, a rapid POC PSA test using a PSA test strip is easy to administer and preliminary data suggest a good correlation with standard venous PSA testing. The development of such a test may improve access to PC screening for high-risk individuals. Continued optimization and validation of our POC test is ongoing. 1. Curr Res Biotechnol 2021;3:288-299. Clinical trial information: N/A.

In-Depth Glycoproteomic Assay of Urinary Prostatic Acid Phosphatase.

Prostate-specific antigen (PSA) is a well-known clinical biomarker in prostate cancer (PCa) diagnosis, but a better test is still needed, as the serum-level-based PSA quantification exhibits limited specificity and comes with poor predictive value. Prior to PSA, prostatic acid phosphatase (PAP) was used, but it was replaced by PSA because PSA improved the early detection of PCa. Upon revisiting PAP and its glycosylation specifically, it appears to be a promising new biomarker candidate. Namely, previous studies have indicated that PAP glycoforms differ between PCa and non-PCa individuals. However, an in-depth characterization of PAP glycosylation is still lacking. In this study, we established an in-depth glycoproteomic assay for urinary PAP by characterizing both the micro- and macroheterogeneity of the PAP glycoprofile. For this purpose, PAP samples were analyzed by capillary electrophoresis coupled to mass spectrometry after affinity purification from urine and proteolytic digestion. The developed urinary PAP assay was applied on a pooled DRE (digital rectal examination) urine sample from nine individuals. Three glycosylation sites were characterized, namely N94, N220, and N333, via N-glycopeptide analysis. Taking sialic acid linkage isomers into account, a total of 63, 27, and 4 N-glycan structures were identified, respectively. The presented PAP glycoproteomic assay will enable the determination of potential glycomic biomarkers for the early detection and prognosis of PCa in cohort studies.

Portable SERS-based lateral flow immunoassay strips with self-calibration for detection of a prostate cancer biomarker

Serum prostate-specific antigen (PSA) is thought to be the most vital indicator for early identification, staging and monitoring of prostate cancer (PCa). Although lateral flow immunoassay (LFA) has demonstrated limitless promise for point-of-care testing (POCT) and has drawn increasing interest and attention, there are significant restrictions on the assay's sensitivity and quantitative capability. Surface-enhanced Raman spectroscopy-based LFA (SERS-LFA) technique integrates the great sensitivity of SERS with the simplicity, rapidity, and usability of the LFA technique, making it ideal for POCT. In this paper, we propose a sensitive self-calibrating SERS-LFA platform, which uses Au@MBN@Ag@PSA NPs as a SERS immunoprobe for the specific recognition of PSA and loads graphene oxide/gold nanoparticles (GO/Au NPs) on nitrocellulose (NC) membranes as an internal standard (IS) molecule. The SERS-LFA platform's detection accuracy is increased through dynamic calibration of the characteristic signals, which is accomplished by detecting the immunoprobe and IS signals simultaneously and computing their respective signal intensity ratios. The self-calibrated SERS-LFA platform demonstrated a 1.65-fold improvement in reproducibility over the conventional SERS-LFA, and PSA could only be detected to a limit of 0.08 ng/mL, meaning that it was 3.5-fold lower than the conventional SERS-LFA platform. The spike recovery experiments yielded recoveries of 96.16∼104.53% with RSD values of 9.37%, 8.66%, and 3.49%, respectively, demonstrating that our self-calibrated SERS-LFA platform for PSA quantification has an acceptable level of precision and has great prospect for early screening of PCa and other diseases.

Electrochemical aptasensor based on 3D graphene aerogel for prostate specific antigen detection

Prostatic cancer threatens the lives and health of numerous male patients all over the world. As a single-chain glycoprotein, prostate specific antigen (PSA) can be used to perform prostate cancer screening. At present, there are still problems such as time-consuming and low sensitivity in hospital detection. At the same time, electrochemical immunosensor technology has received a lot of attention due to its benefits, including high sensitivity, good selectivity, low usage and cost, and so on. Electrocatalysts are typically used to build electrochemical immunosensors for signal amplification in the recent years to realize sensitive detection of cancer biomarkers such as PSA. In recent years, three-dimensional nanomaterials have been widely used in the study of electrocatalysts, but the study of the sensitivity for PSA detection is still very scarce. The present work reported the application of a 3D graphene aerogel(GA)/AuNPs/Nafion electrochemical platform for highly sensitive PSA quantification. The electrochemical immunosensor has been designed by immobilizing aptamers on the screen-printed electrode (SPE) surface modified by GA/AuNPs/Nafion. Scanning electron microscopy (SEM), Raman spectra, and electrochemical characterization demonstrated the successful combination of GA/AuNPs/Nafion/SPE. Based on electrochemical impedance spectroscopy (EIS), the proposed immunosensor has demonstrated excellent electrochemical performance, exhibiting sensitive and stable responses for electrochemical detection of PSA ranging from 0.05 to 50 ng∙mL−1 with a limit of detection (LOD) of 0.0306 ng∙mL−1. This study has great potential application in PSA detection and provides a valuable reference for point-of-care testing (POCT) of prostate cancer.

Transformation of proteins into reproductive DNA templates for sensitive quantification of PSA

A switch DNA template was designed to transform proteins into linear DNA strands of 97 nt. The linear DNA was subjected to quantitative polymerase chain reaction (qPCR) to determine the initial copy number, which correlated positively with the protein concentration. A restriction endonuclease was used to remove background amplification. Using prostate-specific antigen (PSA) as a protein model, the established method quantified PSA in the range of 10−18-10−13 mol/mL (detection limit = 0.034 pg/mL) with an R2 of 0.974. Good repeatability and specificity of the method were demonstrated. The established method was successfully applied for the quantification of serum PSA levels in women. Significant differences in PSA levels were observed between healthy participants and polycystic ovary syndrome patients.

Prostate specific antigen quantification in human serum supported by the designed four-in-one octabranched peptides and AgNPs-based signal amplifier

BackgrounIt remains challenging for biosensors to directly detect clinical targets in complex biological media with high selectivity and low fouling. MethodsHerein, an antifouling and ultrasensitive biosensor supported by the designed four-in-one octabranched peptides and signaling amplification strategy of silver nanoparticles (AgNPs) was constructed for prostate specific antigen (PSA) quantification in human serum. Chondroitin sulfate functionalized polyaniline (PANI) nanowires and gold nanoparticles (AuNPs) were electrodeposited onto the electrode in sequence to promote electrons transport, and followed by the attachment of the designed octabranched peptides. Significant findingsThe peptides were specially designed to contain four structural domains, namely anchoring domain (CC), linking domain (PPPP), antifouling domain (EKEKEKE), and recognition domain (HSSKLQK). AgNPs loaded on graphene oxide were assembled onto peptides as a signal amplification strategy. The peptides were specifically sheared off by PSA, resulting in a significantly reduced electrochemical response that can be used to sensitively indicate PSA concentration. The antifouling biosensor exhibited a linear response range from 1 × 10−14 to 1 × 10−6 M, with a low detection limit of 1.33 × 10−15 M. Furthermore, the biosensor was employed to detect PSA in clinical samples based on the four-in-one octabranched peptides, indicating feasibility of the biosensor for early clinical diagnosis.

Software-Assisted Data Processing Workflow for Intact Glycoprotein Mass Spectrometry.

Intact protein analysis by mass spectrometry is important for several applications such as assessing post-translational modifications and biotransformation. In particular, intact protein analysis allows the detection of proteoforms that are commonly missed by other approaches such as proteolytic digestion followed by bottom-up analysis. Two quantification methods are mainly used for intact protein data quantification, namely the extracted ion and deconvolution approaches. However, a consensus with regard to a single best practice for intact protein data processing is lacking. Furthermore, many data processing tools are not fit-for-purpose and, as a result, the analysis of intact proteins is laborious and lacks the throughput required to be implemented for the analysis of clinical cohorts. Therefore, in this study, we investigated the application of a software-assisted data analysis and processing workflow in order to streamline intact protein integration, annotation, and quantification via deconvolution. In addition, the assessment of orthogonal data sets generated via middle-up and bottom-up analysis enabled the cross-validation of cleavage proteoform assignments present in seminal prostate-specific antigen (PSA). Furthermore, deconvolution quantification of PSA from patients' urine revealed results that were comparable with manually performed quantification based on extracted ion electropherograms. Overall, the presented workflow allows fast and efficient processing of intact protein data. The raw data is available on MassIVE using the identifier MSV000086699.

Trans-Cleavage of the CRISPR-Cas12a-aptamer system for one-step antigen detection.

Rapid detection of prostate-specific antigen (PSA) is pivotal for the early screening of prostate cancer (PCa). Here, we devise a one-step, amplification-free fluorescent detection strategy for PSA, employing the trans-cleavage principle of a CRISPR-Cas12a-aptamer system. This method offers a linear range of 0.31-5 ng mL-1 and a detection limit of 0.16 ng mL-1. The high-confidence quantification of PSA is demonstrated through the analysis of real samples, effectively distinguishing between PCa patients and healthy individuals.

A Novel, Quick, and Reliable Smartphone-Based Method for Serum PSA Quantification: Original Design of a Portable Microfluidic Immunosensor-Based System.

Simple SummaryProstate cancer (PCa) is the most frequently diagnosed malignancy and second most common cause of cancer-related death in males. An early diagnosis is crucial to improve the prognosis. Prostate-Specific Antigen (PSA) is the most widely used biomarker for PCa, but this type of biomarker analysis is performed in centralized laboratories, delaying the diagnosis and initiation of treatment. Our team has developed a miniaturized platform for portable PSA quantification to overcome this shortcoming. It includes a microfluidic chip, immune capture of PSA by magnetic microbeads, and electrochemical quantification. The utilization of a micro-potentiostat allows PSA levels to be read on a smartphone in less than 30 min. This technique was found to offer a fast, easy, specific, sensitive, and reproducible method for PSA quantification. Further research is warranted to verify these findings and explore its potential application at all health care levels.We describe a versatile, portable, and simple platform that includes a microfluidic electrochemical immunosensor for prostate-specific antigen (PSA) detection. It is based on the covalent immobilization of the anti-PSA monoclonal antibody on magnetic microbeads retained in the central channel of a microfluidic device. Image flow cytometry and scanning electron microscopy were used to characterize the magnetic microbeads. A direct sandwich immunoassay (with horseradish peroxidase-conjugated PSA antibody) served to quantify the cancer biomarker in serum samples. The enzymatic product was detected at −100 mV by amperometry on sputtered thin-film electrodes. Electrochemical reaction produced a current proportional to the PSA level, with a linear range from 10 pg mL−1 to 1500 pg mL−1. The sensitivity was demonstrated by a detection limit of 2 pg mL−1 and the reproducibility by a coefficient of variation of 6.16%. The clinical performance of this platform was tested in serum samples from patients with prostate cancer (PCa), observing high specificity and full correlation with gold standard determinations. In conclusion, this analytical platform is a promising tool for measuring PSA levels in patients with PCa, offering a high sensitivity and reduced variability. The small platform size and low cost of this quantitative methodology support its suitability for the fast and sensitive analysis of PSA and other circulating biomarkers in patients. Further research is warranted to verify these findings and explore its potential application at all healthcare levels.

Light Absorption Measurement With a CMOS Biochip for Quantitative Immunoassay Based Point-of-Care Applications.

We present a CMOS biochip-based photometer for quantitative immunoassay diagnostics. The photometer quantifies the concentration of antigens based on light absorption, which allows for a low-cost implementation without expensive optical components. We propose a light controller to lower the start-up and settling time of the light source to 30 seconds, to facilitate fast measurement starts, and to decrease the overall measurement times. The application-specific integrated circuit (ASIC) contains a 6 x 7-sensor array with 100 μm x 100 μm photodiodes that serve as signal transducers. The ASIC was developed in a normal 0.35- μm CMOS technology, avoiding the need for expensive post-CMOS processes. We present our strategy for the assembly of the ASIC and the immobilization of antibodies. For its first time, we demonstrate the quantification of prostate specific antigen (PSA) with an optoelectronic CMOS biochip using this approach. A PSA immunoassay is performed on the top surface of the CMOS sensor array, enzyme kinetics and PSA concentration are measured within 6 minutes with a limit of detection (LoD) of 0.5 ng/ml, which meets clinical testing requirements. We achieve an overall coefficient of variation (CV) of 7%, which is good compared to other point-of-care (PoC) systems.

Highly portable quantitative screening test for prostate-specific antigen at point of care.

Prostate cancer (PCa) is the second most diagnosed cancer among men. Targeted PCa screening may decrease PCa-specific mortality. Prostate-specific antigen (PSA) is the most reliable and widely accepted tumor biomarker for screening and monitoring PCa status. However, in many settings, quantification of serum PSA requires access to centralized laboratories. In this study, we describe a proof-of-concept rapid test combined with a highly portable Cube™ reader for quantification of total PSA from a drop of serum within 20 min. We demonstrated the application of gold nanoshells as a label for lateral flow assay with significant increase in the measured colorimetric signal intensity to achieve five times lower detection limit when compared to the traditionally used 40 nm gold nanosphere labels, without a need for any additional signal amplification steps. We first optimized and evaluated the performance of the assay with commercially available total PSA calibrators. For initial validation with commercially available ACCESS Hybritech PSA calibrator, a detection range of 0.5–150 ng/mL was achieved. We compared the performance of our total PSA test with IMMULITE analyzer for quantification of total PSA in archived human serum samples. On preliminary testing with archived serums samples and comparison with IMMULITE total PSA assay, a correlation of 0.95 (p < .0001) was observed. The highly portable quantitative screening test for PSA described in this study has the potential to make PCa screening more accessible where diagnostic labs and automated immunoassay systems are not available, to reduce therapeutic turnaround time, to streamline clinical care, and to direct patient care for both initial screening and for post-treatment monitoring of patients.

Bioinformatic analysis of dysregulated proteins in prostate cancer patients reveals putative urinary biomarkers and key biological pathways.

Prostate cancer (PCa) is one of the most common cancer types among men. The quantification of prostate-specific antigen used for PCa detection has revealed limited applicability. Thus, it is crucial to identify new minimally invasive biomarkers for PCa. It is believed that the integration of proteomics data from different studies is vital for identifying new biomarkers for PCa, but studies carried out in this regard have few converging results. Using a different approach, this study aimed to unveil molecular features consistently dysregulated in PCa and potential urinary biomarkers for PCa. The novelty of this analysis relies on the comparison of urinary and tissue proteomes from PCa patients and consequent exclusion of kidney and bladder cancer interference. The conducted bioinformatic analysis revealed molecular processes dysregulated in urine from PCa patients that mirror the alterations in prostate tumor tissue. To identify putative urinary biomarkers, proteins previously detected in kidney and bladder tissues were eliminated from the final list of potential urinary biomarkers for PCa. After a detailed analysis, MSMB, KLK3, ITIH4, ITIH2, HPX, GP2, APOA2 and AZU1 proteins stood out as candidate urinary biomarkers for PCa.

ZnO Nanorod FET Biosensors With Enhanced Sensing Performance: Design Issues for Rational Geometry Selection

ZnO nanorod field effect transistor (FET) biosensors enable ultrasensitive, rapid and label free detection of biomolecules. However, the fabrication of these nanorods without any design guideline results in poor signal to noise ratio, limiting their commercial deployment. The various forces operating within the spacing of the nanorods may prevent complete penetration of the liquid for large aspect ratios and hence mere enhancement of the geometric surface area may not yield the optimum output which indicates the intricacies involved in the design of such sensors. The present work consistently models the analyte and the device regions of the sensor by transforming the understanding of the transduction mechanism of biomolecule capture in nanowire FETs into nanorod FET structure and integrating the spacing dependent liquid penetration depth along with the various temporal fluctuations of the sensor to enhance the signal to noise ratio ( SNR ) and lower the molecule detection limit(MDL). Simulation results, verified experimentally for prostate specific antigen (PSA) shows that the optimal geometry does not correspond to the maximum surface area. Instead it is dependent on the developed surface potentials after receptor immobilization and ligand capture which vary non-monotonically with nanorod radius due to nonlinear dependence of buffer penetration for high aspect ratios. This approach has significantly increased the SNR leading to reliable quantification of PSA in human serum with MDL reduced by almost three orders of magnitude in comparison to recent reports. In summary, this work brings the ZnO nanorod sensors a step closer towards practical application for early diagnosis.

Catalytic Gold Deposition for Ultrasensitive Optical Immunosensing of Prostate Specific Antigen.

A major challenge in the development of bioanalytical methods is to achieve a rapid and robust quantification of disease biomarkers present at very low concentration levels in complex biological samples. An immunoassay platform is presented herein for ultrasensitive and fast detection of the prostate-specific antigen (PSA), a well-recognized cancer biomarker. A sandwich type immunosensor has been developed employing a detection antibody labeled with inorganic nanoparticles acting as tags for further indirect quantification of the analyte. The required high sensitivity is then achieved through a controlled gold deposition on the nanoparticle surface, carried out after completing the recognition step of the immunoassay, thus effectively amplifying the size of the nanoparticles from nm to µm range. Due to such an amplification procedure, quantification of the biomolecule could be carried out directly on the immunoassay plates using confocal microscopy for measurement of the reflected light produced by gold-enlarged nanostructures. The high specificity of the immunoassay was demonstrated with the addition of a major abundant protein in serum (albumin) at much higher concentrations. An extremely low detection limit for PSA quantification (LOD of 1.1 fg·mL−1 PSA) has been achieved. Such excellent LOD is 2–3 orders of magnitude lower than the clinically relevant PSA levels present in biological samples (4–10 ng·mL−1) and even to monitor eventual recurrence after clinical treatment of a prostate tumor (0.1 ng·mL−1). In fact, the broad dynamic range obtained (4 orders of magnitude) would allow the PSA quantification of diverse samples at very different relevant levels.

Towards the differential diagnosis of prostate cancer by the pre-treatment of human urine using ionic liquids

Prostate specific antigen (PSA) is the most widely used clinical biomarker for the diagnosis and monitoring of prostate cancer. Most available techniques for PSA quantification in human fluids require extensive sample processing and expensive immunoassays that are often unavailable in developing countries. The quantification of PSA in serum is the most common practice; however, PSA is also present in human urine, although less used in diagnosis. Herein we demonstrate the use of ionic-liquid-based aqueous biphasic systems (IL-based ABS) as effective pre-treatment strategies of human urine, allowing the PSA detection and quantification by more expedite equipment in a non-invasive matrix. If properly designed, IL-based ABS afford the simultaneous extraction and concentration of PSA (at least up to 250-fold) in the IL-rich phase. The best ABS not only allow to concentrate PSA but also other forms of PSA, which can be additionally quantified, paving the way to their use in differential prostate cancer diagnosis.

Triplexed CEA-NSE-PSA Immunoassay Using Time-Gated Terbium-to-Quantum Dot FRET

Time-gated Förster resonance energy transfer (TG-FRET) between Tb complexes and luminescent semiconductor quantum dots (QDs) provides highly advantageous photophysical properties for multiplexed biosensing. Multiplexed Tb-to-QD FRET immunoassays possess a large potential for in vitro diagnostics, but their performance is often insufficient for their application under clinical conditions. Here, we developed a homogeneous TG-FRET immunoassay for the quantification of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and prostate-specific antigen (PSA) from a single serum sample by multiplexed Tb-to-QD FRET. Tb–IgG antibody donor conjugates were combined with compact QD-F(ab’)2 antibody acceptor conjugates with three different QDs emitting at 605, 650, and 705 nm. Upon antibody–antigen–antibody sandwich complex formation, the QD acceptors were sensitized via FRET from Tb, and the FRET ratios of QD and Tb TG luminescence intensities increased specifically with increasing antigen concentrations. Although limits of detection (LoDs: 3.6 ng/mL CEA, 3.5 ng/mL NSE, and 0.3 ng/mL PSA) for the triplexed assay were slightly higher compared to the single-antigen assays, they were still in a clinically relevant concentration range and could be quantified in 50 µL serum samples on a B·R·A·H·M·S KRYPTOR Compact PLUS clinical immunoassay plate reader. The simultaneous quantification of CEA, NSE, and PSA at different concentrations from the same serum sample demonstrated actual multiplexing Tb-to-QD FRET immunoassays and the potential of this technology for translation into clinical diagnostics.

A Sensitive Aptamer-Based Biosensor for Electrochemical Quantification of PSA as a Specific Diagnostic Marker of Prostate Cancer.

The current project aimed to design a simple, highly sensitive, and economical label-free electrochemical aptasensor for determination of prostate-specific antigen (PSA), as the gold standard biomarker for prostate cancer diagnosis. The aptasensor was set up using a screen-printed carbon electrode (SPCE) modified by gold nanoparticles (Au NPs) conjugated to thiolated aptamers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were implemented for electrochemical (EC) characterization of the aptasensor. The determination of PSA was also performed through differential pulse voltammetry (DPV) in [Fe (CN) 6]3-/4- electrolyte solution. The present aptasensor was shown an outstanding linear response in the concentration range of 1 pg/mL - 200 ng/mL with a remarkably lower limit of detection of 0.077 pg/mL. The optimum concentration for PSA separation and the optimum incubation time for antigen-aptamer binding were determined by observing and electing the highest electrochemical responses in a specified time or concentration. According to the results of the specificity tests, the designed aptasensor did not show any significant interactions with other analytes in real samples. Clinical functionality of the aptasensor was appraised in serum samples of healthy individuals and patients examining the PSA level through the fabricated aptasensor and the reference methods. Both methods are comparable in sensitivity. The present fabricated PSA aptasensor with substantial characteristics of ultra- sensitivity and cost-effectiveness can be conventionally built and used for the routine check-up of the men for prostate problems.

A novel nano copper complex: potentiometry, DFT and application as a cancer prostatic biomarker for the ultrasensitive detection of human PSA.

Worldwide, prostate cancer is considered to be one of the three most commonly occurring cancers amongst the male population. Clinically, early detection of diverse forms of cancer before they spread and become incurable plays an important role in treatment strategy. Therefore, the development of fast, accurate, sensitive, and low-cost analytical methodologies and techniques for the detection of cancer biomarkers is an attractive research area for scientists globally. Herein, a Schiff base ligand (A1) was prepared via the refluxing of 3-aminobenzoic acid with 1,2-phenylenediamine. After that, a nano Cu complex (N1) was synthesized by reacting A1 with copper chloride. The produced A1 and N1 were characterized using several techniques to determine their physicochemical properties. A density functional theory study was carried out to rationalize the experimental work and support the obtained results. Moreover, the nano Cu complex (N1) was used for the fabrication of a potentiometric membrane biosensor for the early detection of the prostate-specific antigen (PSA). The results reveal that the electrode displays a stable Nernstian response of 29.26 ± 0.87 mV per decade for PSA in a linear dynamic range of 5.0 pg mL-1-10.0 ng mL-1, in a pH range of 6.5-9.2, with a short response time of 25 ± 5 s. The lifetime was between 5-7 weeks under different storage conditions. The detection (LOD) and quantification (LOQ) limits were 0.098 and 0.297 pg mL-1, respectively. The presence of different interfering species on the potentiometric biosensor response against PSA was investigated. The sensing mechanism of N1 toward PSA and the applicability of the developed electrode for the screening and quantification of PSA in real serum samples were also studied.