ABSTRACT
The establishment of novel disruptive technologies represents a common requirement for the sustainable development as reported in the 2030 agenda established by United Nations. As demonstrated by the Covid-19 pandemic, and furtherly highlighted by the current global challenges, i.e. precision agriculture, decentralized testing, personalized medicine, the field of portable devices is growing day-by-day. Relatively to the electrochemical portable strips, globally represented by glucose strips for diabetes patients, the use of plastic-based products is still very high. In this work, two bacterial polymers have been deeply characterized and compared with the gold standard polyester that is the most used material to produce printed electrochemical strips. In particular, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV with micro-fibrillated cellulose (MFC), namely PHBV/MFC, have been produced with different porosities and have been morphologically, mechanically and electrochemically characterized. Scanning electron microscopy, contact angle, tensil tests, cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, stripping voltammetry and chronoamperometry have been used to evaluate and confirm the suitability of PHBV-based substrates for future sustainable application in the (bio)electroanalytical field. In particular these novel substrates have been applied towards the development of two sensing platforms, namely iron ions and organophosphate pesticides. As shown, in comparison with the gold standard polyester for sensors and biosensors development, the use of PHBV-based substrates allowed to reach similar detection limit and repeatability. In particular, iron ions were detected down to 140 and 150 ppb and dichlorvos was detect with an inhibition biosensor down to 0.4 and 0.5 ppb, respectively for PHBV and PHBV/MFC. These novel substrates may represent a starting point towards the development of sustainable platforms for decentralized applications. • PHBV-based materials are 100% bio-compatible and bio-degradable. • Cellulose merging is able to provide new functionalities. • Polyester-based substrates can be replaced by more sustainable ones. • A novel starting point to make sustainable electrochemical (bio)sensors. • Facile detection of iron ions and organophosphate as the case of study. [ FROM AUTHOR]
ABSTRACT
The establishment of novel disruptive technologies represents a common requirement for the sustainable development as reported in the 2030 agenda established by United Nations. As demonstrated by the Covid-19 pandemic, and furtherly highlighted by the current global challenges, i.e. precision agriculture, decentralized testing, personalized medicine, the field of portable devices is growing day-by-day. Relatively to the electrochemical portable strips, globally represented by glucose strips for diabetes patients, the use of plastic-based products is still very high. In this work, two bacterial polymers have been deeply characterized and compared with the gold standard polyester that is the most used material to produce printed electrochemical strips. In particular, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV with micro-fibrillated cellulose (MFC), namely PHBV/MFC, have been produced with different porosities and have been morphologically, mechanically and electrochemically characterized. Scanning electron microscopy, contact angle, tensil tests, cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, stripping voltammetry and chronoamperometry have been used to evaluate and confirm the suitability of PHBV-based substrates for future sustainable application in the (bio)electroanalytical field. In particular these novel substrates have been applied towards the development of two sensing platforms, namely iron ions and organophosphate pesticides. As shown, in comparison with the gold standard polyester for sensors and biosensors development, the use of PHBV-based substrates allowed to reach similar detection limit and repeatability. In particular, iron ions were detected down to 140 and 150 ppb and dichlorvos was detect with an inhibition biosensor down to 0.4 and 0.5 ppb, respectively for PHBV and PHBV/MFC. These novel substrates may represent a starting point towards the development of sustainable platforms for decentralized applications.
ABSTRACT
At the end of December 2019, an epidemic form of respiratory tract infection now named COVID-19 emerged in Wuhan, China. It is caused by a newly identified viral pathogen, the severe acute respiratory syndrome coronavirus (SARS-CoV-2), which can cause severe pneumonia and acute respiratory distress syndrome. On January 30, 2020, due to the rapid spread of infection, COVID-19 was declared as a global health emergency by the World Health Organization. Coronaviruses are enveloped RNA viruses belonging to the family of Coronaviridae, which are able to infect birds, humans and other mammals. The majority of human coronavirus infections are mild although already in 2003 and in 2012, the epidemics of SARS-CoV and Middle East Respiratory Syndrome coronavirus (MERS-CoV), respectively, were characterized by a high mortality rate. In this regard, many efforts have been made to develop therapeutic strategies against human CoV infections but, unfortunately, drug candidates have shown efficacy only into in vitro studies, limiting their use against COVID-19 infection. Actually, no treatment has been approved in humans against SARS-CoV-2, and therefore there is an urgent need of a suitable vaccine to tackle this health issue. However, the puzzled scenario of biological features of the virus and its interaction with human immune response, represent a challenge for vaccine development. As expected, in hundreds of research laboratories there is a running out of breath to explore different strategies to obtain a safe and quickly spreadable vaccine; and among others, the peptide-based approach represents a turning point as peptides have demonstrated unique features of selectivity and specificity toward specific targets. Peptide-based vaccines imply the identification of different epitopes both on human cells and virus capsid and the design of peptide/peptidomimetics able to counteract the primary host-pathogen interaction, in order to induce a specific host immune response. SARS-CoV-2 immunogenic regions are mainly distributed, as well as for other coronaviruses, across structural areas such as spike, envelope, membrane or nucleocapsid proteins. Herein, we aim to highlight the molecular basis of the infection and recent peptide-based vaccines strategies to fight the COVID-19 pandemic including their delivery systems.