Development of bio-sensing platforms for applications in sport medicine and in real-time environmental monitoring

My research activity, carried out during the period of the doctorate, concerned the development of specific bio-sensing platforms to be used for applications in sport medicine and in real-time environmental monitoring. During the first year of my doctorate I developed a disposable biosensor for lactate determination in saliva. The biosensor has been evaluated in terms of analytical performance and then tested with real saliva specimens. I also proposed a new, simple and effective protocol for saliva sample pretreatment which could be used for measurements outside the laboratory. The lactate biosensor was also compared to a commercial portable lactate analyzer, demonstrating a good correlation. This study was published in SENSORS AND ACTUATORS B, CHEMICAL, ISSN: 0925-4005. Throughout the second year I was engaged in the development of a biosensing assay for the detection of microcystins (MCs). This study makes part of a national project called "Acquasense" (Ministero per lo Sviluppo Economico, Industria 2015, Bando Nuove Tecnologie per il Made in Italy), which deals with the determination of chemical pollutants in drinking water, including MCs. Based on the purposes of the project for a simple and sensitive assay, I proposed an enzyme inhibition colorimetric method that uses the protein phosphatase type 2A (PP2A) as recognition element. The colorimetric assay has been applied in surface water, drinking water and a culture medium selective for cyanobacterial growth, with consequent release of MCs. The results obtained were compared to a standard chromatographic technique (UHPLC-DAD). This research, made in collaboration with the Departments of Biology and Inorganic Chemistry of the University of Rome, “Tor Vergata”, was the subject of two publications: BIOSENSORS & BIOELECTRONICS, ISSN: 0956-5663 and PROCEDIA ENGINEERING, ISSN: 1877-7058. From the half of the second year until the end of the third year of my doctorate, I have also been involved in a European project entitled “Sensing toxicants research in Marine waters make Sense using biosensors”, whose acronym is SMS and deals with the determination of marine water contaminants in coastal areas, including algal toxins. My concern was to develop novel sensing platforms, to be integrated in sensing devices, for the determination of two marine toxins, Okadaic Acid (OA) and Domoic Acid (DA), directly in marine water. My original idea was to develop an aptamer-based sensor for OA detection. To do this, I functionalized and tested different specific aptamers for OA. Unfortunately, none of these aptameric sequences demonstrated high affinity for its target. For this reason, I had to relinquish the idea to use aptamers as recognition elements to detect low levels of the mentioned toxins. Considering that OA is a potent inhibitor of the enzyme PP2A, I proposed the same colorimetric method, mentioned above, for its determination. After applying the assay in different seawater samples, I have been actively participated in its integration within a miniaturized automated apparatus (prototype colorimetric device) able to perform real-time monitoring of the toxin. The prototype device was tested and compared to the non-automated enzymatic assay. The results correlate well. As for the detection of DA, I focused my attention on the development of a competitive ELIMC (Enzyme-Linked Immuno-Magnetic Colorimetric) assay that uses antibodies as recognition elements. I proposed a format based on a single step competition procedure, which guarantees a short incubation time, combined with a colorimetric detection. The integration of the ELIMC assay in an automated apparatus and recovery experiments are still in progress.