{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,16]],"date-time":"2025-12-16T12:21:49Z","timestamp":1765887709634,"version":"build-2065373602"},"reference-count":50,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2015,5,22]],"date-time":"2015-05-22T00:00:00Z","timestamp":1432252800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 \u00d7 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 \u00b5g\/mL). The best performance of the microarray platform was seen at 100 \u00b5g\/mL of the capture antibody concentration (LOD was 100 fg\/mL). The platform then was subsequently evaluated for a titration series of  serum-spiked hK2 samples. The developed platform utilizes only 15 \u00b5L of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg\/mL in PBS buffer and 1 pg\/mL in serum with a dynamic range of 106 (10\u22124 to 102 ng\/mL).<\/jats:p>","DOI":"10.3390\/s150511972","type":"journal-article","created":{"date-parts":[[2015,5,26]],"date-time":"2015-05-26T04:16:36Z","timestamp":1432613796000},"page":"11972-11987","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["A Highly Sensitive Porous Silicon (P-Si)-Based Human  Kallikrein 2 (hK2) Immunoassay Platform toward  Accurate Diagnosis of Prostate Cancer"],"prefix":"10.3390","volume":"15","author":[{"given":"Sang","family":"Lee","sequence":"first","affiliation":[{"name":"Bioengineering Laboratory, RIKEN, Saitama 3510198, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazuo","family":"Hosokawa","sequence":"additional","affiliation":[{"name":"Bioengineering Laboratory, RIKEN, Saitama 3510198, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Soyoun","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Dongguk University, Seoul 100715, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ok","family":"Jeong","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Inje University, Gimhae-si 621-749, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans","family":"Lilja","sequence":"additional","affiliation":[{"name":"Department of Translational Medicine, Lund University, Sk\u00e5ne University Hospital in Malm\u00f6, Malm\u00f6 20502, Sweden"},{"name":"Departments of Laboratory Medicine, Surgery (Urology), and Medicine (GU Oncology),  Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA"},{"name":"Institute for Biosciences and Medical Technology, University of Tampere, Tampere 33800, Finland"},{"name":"Nuffield Department of Surgical Sciences, University of Oxford, Oxford OX3 7DQ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas","family":"Laurell","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Dongguk University, Seoul 100715, Korea"},{"name":"Department Biomedical Engineering, Lund University, Lund 22100, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mizuo","family":"Maeda","sequence":"additional","affiliation":[{"name":"Bioengineering Laboratory, RIKEN, Saitama 3510198, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1600","DOI":"10.1373\/clinchem.2008.105189","article-title":"Utility of kallikrein-related peptidases (KLKs) as cancer biomarkers","volume":"54","author":"Emami","year":"2008","journal-title":"Clin. 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