Towards sarcosine determination in urine for prostatic carcinoma detection

Sarcosine, a potential biomarker for prostate cancer, can be detected in a solid state enzyme based biosensor using sarcosine oxidase, with particle immobilised reagents. A novel fusion protein of the fluorescent protein, mCherry, sarcosine oxidase (SOx), and the polypeptide R5 (R52-mCherry-SOx-R5-6H), was explored, which allowed self-immobilization on silica microparticles and long-term (90 days +) retention of activity, even at room temperature. In contrast, commercial wildtype SOx lost activity in a few days. A silica-R52-mCherry-SOx-R5-6H microparticle sensor for determination of sarcosine in urine, linked the SOx coproduct, H2O2, to a measurement catalysed by horseradish peroxidase (HRP) immobilised on silica, in the presence of Amplex Ultrared (AR) to generate fluorescence at 582 nm. Silica microparticles carrying all the reagents (R52-mCherry-SOx-R5-6H, HRP and AR) were used to produce a silica-microparticle biosensor which responded to sarcosine at micromolar levels. Interference by amino acids and uric acid was examined and it was found that the silica-reagent carrying system could be calibrated in urine and responded across the clinically relevant concentration range. This contrasted with similar assays using commercial SOx, where interference inhibited the sarcosine signal measurement in urine. The microparticle biosensor was tested in urine from healthy volunteers and prostate cancer patients, showing higher concentrations of sarcosine in cancer patients consistent with previous reports of elevated sarcosine levels.BBSRC/EPSRC funded Grant No. BB/L014130/1 Gates Cambridge Trust Generalitat Valenciana and European commission for its postdoctoral grant (APOSTD/113/2016) Generalitat Valenciana (PROMETEO 2016/109

New silica based adsorbent material from rice straw and its in-flow application to nitrate reduction in waters: Process sustainability and scale-up possibilities

[EN] This paper shows a particular example to move to a sustainable circular economical process from valorization of rice straw ashes by developing a green synthesis for obtaining a useful sub-product. This strategy can palliate negative effects of the agriculture waste practices on the environment and also the obtained silica reduced nitrate content in waters. It is demonstrated that the silica synthesis developed at lab was scalable more than a hundred times with good results. Adsorption studies of nitrate in standards and real well waters at lab scale and scaling-up provided similar results. Adsorption values near to 15 mg/g for nitrate standards and 8.5 mg/g for well water were obtained until achieving the initial nitrate concentration. Experimental breakthrough curves fitted to Thomas model, which gave similar results for adsorption capacities. The adsorption capacity was checked with that obtained by a commercial resin, providing improved results. The method at large scale was compared with industrial traditional methods and green adsorbents.The authors are grateful to EU (EASME LIFE and CIP ECO-Innovation) LIBERNITRATE. LIFE 16 ENV/ES/000419; EU FEDER and the Gobierno de Espana MCIU-AEI (CTQ2017-90082-P) and the Generalitat Valenciana (PROMETEO 2020/078) and EU FEDER-Generalitat Valenciana (ID-FEDER/2018/049) for the financial support received. H. R. Robles-Jimarez expresses his grateful to EU-LIBERNITRATE. L. Sanjuan-Navarro expresses his gratitude for the FPU-grant (MCIU-AEI) .Robles-Jimarez, H.; Sanjuan-Navarro, L.; Jornet-Martínez, N.; Primaz, C.; Teruel-Juanes, R.; Molins-Legua, C.; Ribes-Greus, A.... (2022). New silica based adsorbent material from rice straw and its in-flow application to nitrate reduction in waters: Process sustainability and scale-up possibilities. Science of The Total Environment. 805:1-12. https://doi.org/10.1016/j.scitotenv.2021.15031711280

Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

Zein as biodegradable material for effective delivery of alkaline phosphatase and substrates in biokits and biosensors

A biodegradable material, zein, is proposed as a reagent delivery platform for biokits and biosensors based on alkaline phosphatase (ALP) activity/inhibition in the presence of phosphatase substrates. The immobilization and release of both the substrate and/or the active ALP, in a biodegradable and low-cost material such as zein, a prolamin from maize, and in combination with glycerol as plasticizer have been investigated. Three zein-based devices are proposed for several applications: (1) inorganic phosphorus estimation in water of different sources (river, lake, coastal water and tap water) with a detection limit of 0.2mg/L - compared to at least 1mg/L required by legislation, (2) estimation of ALP in saliva and (3) chlorpyrifos control in commercial preparations. The single-use kits developed are low cost, easy and fast to manufacture and are stable for at least 20 days at -20°C, so the zein film can preserve and deliver both the enzyme and substrates.The authors are grateful to Generalitat Valenciana (PROMETEO 2012/045 project and BEFPI/2014/014), Spain and to the Spanish Ministerio de Economía y Competitividad/FEDER (Project CTQ2014-53916-P). NJ expresses her gratitude to PROMETEO program for her predoctoral grant and BEFPI program for her stay grant

Towards sarcosine determination in urine for prostatic carcinoma detection

Sarcosine, a potential biomarker for prostate cancer, can be detected in a solid state enzyme based biosensor using sarcosine oxidase, with particle immobilised reagents. A novel fusion protein of the fluorescent protein, mCherry, sarcosine oxidase (SOx), and the polypeptide R5 (R52-mCherry-SOx-R5-6 H), was explored, which allowed self-immobilization on silica microparticles and long-term (90 days +) retention of activity, even at room temperature. In contrast, commercial wildtype SOx lost activity in a few days. A silica-R52-mCherry-SOx-R5-6H microparticle sensor for determination of sarcosine in urine, linked the SOx coproduct, H2O2, to a measurement catalysed by horseradish peroxidase (HRP) immobilised on silica, in the presence of Amplex Ultrared (AR) to generate fluorescence at 582 nm. Silica microparticles carrying all the reagents (R52-mCherry-SOx-R5-6H, HRP and AR) were used to produce a silica-microparticle biosensor which responded to sarcosine at micromolar levels. Interference by amino acids and uric acid was examined and it was found that the silica-reagent carrying system could be calibrated in urine and responded across the clinically relevant concentration range. This contrasted with similar assays using commercial SOx, where interference inhibited the sarcosine signal measurement in urine. The microparticle biosensor was tested in urine from healthy volunteers and prostate cancer patients, showing higher concentrations of sarcosine in cancer patients consistent with previous reports of elevated sarcosine levels