Screening and testing during the COVID-19 pandemic: An STS perspective

Η παρούσα εργασία αποτελεί μια STS προσέγγιση σχετικά με τους διαγνωστικούς ελέγχους κατά τη διάρκεια της πανδημίας Covid-19. Αρχικά, πραγματοποιείται μια εισαγωγή στο θέμα και εξετάζεται η τρέχουσα κατάσταση σχετικά με τις πολιτικές διαγνωστικών ελέγχων παγκοσμίως. Ακολουθεί βιβλιογραφική ανασκόπηση των όρων “testing” και “screening”, καθώς και ανάλυση των διαφορών μεταξύ των δύο όρων. Αναλύονται οι κύριες τεχνικές “testing” και “screening” που χρησιμοποιήθηκαν κατά τη διάρκεια της πανδημίας. Το κύριο μέρος της εργασίας περιλαμβάνει μια STS ανάλυση βασισμένη σε τεχνικά κείμενα που σχετίζονται με μεθόδους διαγνωστικών ελέγχων. Κάθε μέθοδος μελετάται ξεχωριστά, ενώ, σε ορισμένες περιπτώσεις, εξετάζονται συγκεκριμένες συσκευές που διατίθενται στο εμπόριο. Αυτή η ανάλυση στοχεύει να δείξει ότι οι διαγνωστικές μέθοδοι που χρησιμοποιούνται κατά τη διάρκεια της πανδημίας δεν είναι πολιτικά ουδέτερες. Η εργασία καταλήγει στην αναγκαιότητα ύπαρξης μιας STS προσέγγισης του ζητήματος για δύο λόγους. Πρώτον, κάθε μέθοδος “testing” και “screening”– καθώς και οι πολιτικές που σχετίζονται με αυτές– φαίνεται να έχουν σημαντικό κοινωνικό αντίκτυπο που πρέπει να εξεταστεί περεταίρω. Επιπλέον, μια τέτοια προσέγγιση φαίνεται να οδηγεί σε καλύτερη κατανόηση και βελτιστοποίηση των εν λόγω μεθόδων.This thesis puts forward an STS approach to testing and screening during the Covid-19 pandemic. Initially, this text provides an introduction to the subject and examines the current situation regarding testing policies worldwide. What follows is a bibliographic review of testing and screening, as well as an analysis and demarcation of the differences between the two terms. The main testing and screening techniques utilized during the pandemic are subsequently dissected. The main part of the thesis comprises an STS analysis based on technical texts relating to testing and screening methods. Each method is studied separately, while, in some cases, specific commercially available devices are being examined. This analysis aims to show that the testing and screening methods employed during the pandemic are not politically neutral. In the conclusion, it is suggested that approaching this issue from an STS perspective is necessary for two reasons. Firstly, each testing or screening method –as well as the policies that are associated with them– seem to have an important social impact that needs to be scrutinized. Furthermore, such an approach seemingly leads to a better understanding and optimization of the methods in question

Advancements in SARS-CoV-2 Testing: Enhancing Accessibility through Machine Learning-Enhanced Biosensors

The COVID-19 pandemic highlighted the importance of widespread testing for SARS-CoV-2, leading to the development of various new testing methods. However, traditional invasive sampling methods can be uncomfortable and even painful, creating barriers to testing accessibility. In this article, we explore how machine learning-enhanced biosensors can enable non-invasive sampling for SARS-CoV-2 testing, revolutionizing the way we detect and monitor the virus. By detecting and measuring specific biomarkers in body fluids or other samples, these biosensors can provide accurate and accessible testing options that do not require invasive procedures. We provide examples of how these biosensors can be used for non-invasive SARS-CoV-2 testing, such as saliva-based testing. We also discuss the potential impact of non-invasive testing on accessibility and accuracy of testing. Finally, we discuss potential limitations or biases associated with the machine learning algorithms used to improve the biosensors and explore future directions in the field of machine learning-enhanced biosensors for SARS-CoV-2 testing, considering their potential impact on global healthcare and disease control

Design and development of a biosensor for the rapid detection of SARS-CoV-2

The aim of this thesis is the development of an electrochemical biosensor for the rapid detection of SARS-CoV-2 in biological samples.In the first part of the thesis, the sensing element is developed, based on the immobilization of the natural receptor of the virus, the enzyme ACE2, on the surface of interdigitated electrode capacitors. The results of the biosensor measurements are correlated with the real-time PCR results for the same samples.Then, after the sensor has been verified to function properly, the sensor is integrated into a lab-developed portable device. This device consists of a custom precision electronic circuit that performs impedance measurements. Also, using Bluetooth, the device wirelessly transmits the measurement results to an android mobile application developed in the framework of the thesis.The final stage concerns the packaging of the biosensor and the electronic device, but also the construction of the connector between the two. The packaging of the device and the manufacturing of the connector are done using 3D printing. The packaging of the biosensor is carried out using a photosensitive film, ORDYL SY 300, which is processed by the method of optical lithography.Στόχος αυτής της διατριβής είναι η ανάπτυξη ενός ηλεκτροχημικού βιοαισθητήρα για την ανίχνευση του SARS-CoV-2 σε βιολογικά δείγματα.Στο πρώτο μέρος της διατριβής αναπτύσσεται το αισθητήριο στοιχείο, που βασίζεται στην ακινητοποίηση του φυσικού υποδοχέα του ιού, του ενζύμου ACE2, στην επιφάνεια πυκνωτών ενδοδιαπλεκόμενων ηλεκτροδίων. Τα αποτελέσματα των μετρήσεων του βιοαισθητήρα συσχετίζονται με τα αποτελέσματα της real-time PCR για τα ίδια δείγματα.Στην συνέχεια, αφού έχει επαληθευτεί η ορθή λειτουργία του αισθητήρα, ο αισθητήρας ενσωματώνεται σε μια φορητή συσκευή που αναπτύχθηκε στο εργαστήριο. Αυτή η συσκευή αποτελείται από ένα πρωτότυπο ηλεκτρονικό κύκλωμα ακριβείας που πραγματοποιεί μετρήσεις της σύνθετης αντίστασης. Ακόμα, χρησιμοποιώντας Bluetooth, η συσκευή μεταδίδει ασύρματα τα αποτελέσματα της μέτρησης σε εφαρμογή για κινητά android που αναπτύχθηκε στα πλαίσια της διατριβής.Το τελικό στάδιο αφορά το πακετάρισμα του βιοαισθητήρα και της ηλεκτρονικής συσκευής, αλλά και την κατασκευή της διασύνδεσης μεταξύ των δύο. Το πακετάρισμα της συσκευής και η κατασκευή της διασύνδεσης πραγματοποιούνται με χρήση τρισδιάστατης εκτύπωσης. Το πακετάρισμα του βιοαισθητήρα πραγματοποιείται με την χρήση μιας φωτοευαίσθητης ταινίας, της ORDYL SY 300, η επεξεργασία της οποίας γίνεται με την μέθοδο της οπτικής λιθογραφίας

A Portable Screening Device for SARS-CoV-2 with Smartphone Readout

Since the outbreak of the COVID-19 pandemic, great emphasis has been placed on the development of rapid virus detection devices, the principle of operation of many of which is the detection of the virus structural protein spike. Although several such devices have been developed, most are based on the visual observation of the result, without providing the possibility of its electrical processing. This paper presents a biosensor platform for the rapid detection of spike proteinboth in laboratory conditions and in swab samples from hospitalized patients. The platform consists of a microcontroller-based readout circuit, which measures the capacitance change generated in an interdigitated electrode transducer by the presence of the spike protein. The circuit efficiency is calibrated by its correlation with the capacitance measurement of an LCR meter. The test result is made available in less than 2 min through the microcontroller’s LCD screen, and at the same time, the collected data are sent wirelessly to a mobile application interface. In this way, the continuous and effective screening of SARS-CoV-2 patients is facilitated and enhanced, providing big data statistics of COVID-19 in terms of space and time

Packaging and Optimization of a Capacitive Biosensor and Its Readout Circuit

In pipeline production, there is a considerable distance between the moment when the operation principle of a biosensor will be verified in the laboratory until the moment when it can be used in real conditions. This distance is often covered by an optimization and packaging process. This article described the packaging and optimization of a SARS-CoV-2 biosensor, as well as the packaging of its electronic readout circuit. The biosensor was packed with a photosensitive tape, which forms a protective layer and is patterned in a way to form a well in the sensing area. The well is meant to limit the liquid diffusion, thereby reducing the measurement error. Subsequently, a connector between the biosensor and its readout circuit was designed and 3D-printed, ensuring the continuous and easy reading of the biosensor. In the last step, a three-dimensional case was designed and printed, thus protecting the circuit from any damage, and allowing its operation in real conditions

Design and Testing of a Disposable Flow Cuvette for Continuous Electroporation of a Bioreactor’s Initial Algae Cultivation

Electroporation is a technique applied both in biomedical and biotechnological fields which uses a high-voltage electric current to temporarily destabilize the plasma membrane of living cells, permitting the introduction of small molecules as well as nucleic acids into the cytosol. Besides viral and chemical transfections, this method is a common way to manipulate living cells. However, the majority of electroporation machines available on the market can only work using batch-based cuvettes treating only a few micrograms of cells. To transform cells in the order of several grams in the quickest possible way, it is necessary to use a continuous-flow method. In this work, we present the design, electric and fluid dynamics simulations, construction and testing of a flow cuvette that can adapt to standard electroporator systems. The flow cuvette connected with a peristaltic pump was able to successfully electroporate 20 mL of medium containing microalgae cells in less than 5 min. Microalgae Scenedesmus almeriensis cells were transfected with a fluorescent siRNA oligo as well as magnetically transformed by introducing magnetic nanoparticles in their cytoplasm. The flow cuvette presented here offers a valid tool for the high-throughput transformation/transfection/transfer of both prokaryotic and eukaryotic organisms, especially suitable for bioreactor cultivation and other industrial biotechnological contexts

Design and Testing of a Disposable Flow Cuvette for Continuous Electroporation of a Bioreactor’s Initial Algae Cultivation

Electroporation is a technique applied both in biomedical and biotechnological fields which uses a high-voltage electric current to temporarily destabilize the plasma membrane of living cells, permitting the introduction of small molecules as well as nucleic acids into the cytosol. Besides viral and chemical transfections, this method is a common way to manipulate living cells. However, the majority of electroporation machines available on the market can only work using batch-based cuvettes treating only a few micrograms of cells. To transform cells in the order of several grams in the quickest possible way, it is necessary to use a continuous-flow method. In this work, we present the design, electric and fluid dynamics simulations, construction and testing of a flow cuvette that can adapt to standard electroporator systems. The flow cuvette connected with a peristaltic pump was able to successfully electroporate 20 mL of medium containing microalgae cells in less than 5 min. Microalgae Scenedesmus almeriensis cells were transfected with a fluorescent siRNA oligo as well as magnetically transformed by introducing magnetic nanoparticles in their cytoplasm. The flow cuvette presented here offers a valid tool for the high-throughput transformation/transfection/transfer of both prokaryotic and eukaryotic organisms, especially suitable for bioreactor cultivation and other industrial biotechnological contexts

A Biosensor Platform for Point-of-Care SARS-CoV-2 Screening

The COVID-19 pandemic remains a constant threat to human health, the economy, and social relations. Scientists around the world are constantly looking for new technological tools to deal with the pandemic. Such tools are the rapid virus detection tests, which are constantly evolving and optimizing. This paper presents a biosensor platform for the rapid detection of spike protein both in laboratory conditions and in swab samples from hospitalized patients. It is a continuation and improvement of our previous work and consists of a microcontroller-based readout circuit, which measures the capacitance change generated in an interdigitated electrode transducer by the presence either of sole spike protein or the presence of SARS-CoV-2 particles in swab samples. The circuit efficiency is calibrated by its correlation with the capacitance measurement of an LCR (inductance (L), capacitance (C), and resistance (R)) meter. The test result is made available in less than 2 min through the microcontroller’s LCD (liquid-crystal display) screen, whereas at the same time, the collected data are sent wirelessly to a mobile application interface. The novelty of this research lies in the potential it offers for continuous and effective screening of SARS-CoV-2 patients, which is facilitated and enhanced, providing big data statistics of COVID-19 in terms of space and time. This device can be used by individuals for SARS-CoV-2 testing at home, by health professionals for patient monitoring, and by public health agencies for monitoring the spatio-temporal spread of the virus