1. Αποθετήριο Παραδοτέων Υποτρόφων Δράσεων ΕΣΠΑ Τριτοβάθμιας Εκπαίδευσης 2017-2023
2. Όλο το Αποθετήριο
3. Ερευνητικές ομάδες

Τύπος:	Αναρτημένη ανακοίνωση (poster)
Τίτλος:	3D structured biochip for label-free multi-analyte determinations at the PoN
Συγγραφέας:	[EL] Ζήσης, Γρηγόριος - Κωνσταντίνος[EN] Zisis, Grigorios - Konstantinos [EL] Παπαγεωργιου, Γιώργος[EN] Papageorgiou, Georgios [EL] Αναστασιάδης, Βασίλειος[EN] Anastasiadis, Vasileios [EL] Πέτρου, Παναγιώτα[EN] Petrou, Panagiota [EL] Παπανικολάου, Νικόλαος[EN] Papanikolaou, Nikolaos [EL] Ράπτης, Ιωάννης[EN] Raptis, Ioannis
Ημερομηνία:	21/09/2021
Περίληψη:	Optical biosensors are widely employed in the fast and accurate determination of biomarkers, critical for human health, and harmful substances in food. Several transduction principles have been developed exploiting Si-based integrated photonic devices such as Mach-Zehnder interferometers, ring resonators etc. In addition to those transduction principles, standard Spectroscopic Reflectance (SR) has been investigated and already reached the market. In SR, the reflectance spectrum from the SiO2/Si structure is analyzed by a high- resolution miniaturized spectrometer. Then, the growth of the biomolecular adlayer on the bio-functionalized SiO2 structure, causes a red-shift in the reflectance spectrum that can be correlated to the thickness of the biolayer and thus to the concentration of the analyte under investigation. SR based sensing tools use low-cost biochips suitable for single use applications but the measurement set-up is rather expensive and the possibility of multi-analyte determination at the Point-of-Need (PoN) is questionable. In this work, we introduce for the first time a radical biosensing concept in which reflectance from a SiO2 layer with spatially varying thickness is recorded. The SiO2 layer is engineered by carefully tuned grey- scale lithography followed by dry etching of a SiO2 layer on a Si substrate. The illumination of the structure by a standard and low-cost LED causes a spatial modulation in the reflectance signal that is recorded by the appropriate optical set-up built around a CCD camera. In Fig. 1, the fabrication flow-chart of the biochip is illustrated. The process starts with the growth/deposition of a thick SiO2 layer (e.g. 3μm) followed by application of negative resist and grey-scale e- beam lithography. The last step is dry etching for the transfer of the resist pattern to the underling SiO2 and remaining resist stripping. The slope of the SiO2 structure is adjusted by careful tuning of the resist pattern thickness slope and optimization of dry etching selectivity. In Fig. 2a, the theoretical reflectance for a characteristic SiO2 thickness slope is illustrated along with the theoretical reflectance of the same structure with 1nm biomolecular adlayer. The shift in the reflectance signal, in this spatially thickness-varying substrate is comparable to the red shift in the case of SR on a constant thickness substrate, fig. 2b. Finally, in Fig. 3 the reflectance signal recorded under RGB illumination of a SiO2 structure consisting of 34 areas with linearly changing thickness from 794nm up to 1327nm, by a dedicated set-up equipped with 2Mpixel CCD is illustrated, where the reflectance modulation is in good agreement with the theoretical results presented in Fig. 2a. In the next steps, this novel transduction principle will be applied for the quantitative determination of certain harmful species in food (e.g. Aflatoxin M1), aiming at the application at the Point-of-Need.
Γλώσσα:	Αγγλικά
Τόπος δημοσίευσης:	Turin, Italy
Σελίδες:	1
Θεματική κατηγορία:	[EL] Επιστήμη υλικών, διεπιστημονική προσέγγιση[EN] Materials science, interdisciplinary
Κάτοχος πνευματικών δικαιωμάτων:	© 2021 The Author(s)
Ηλεκτρονική διεύθυνση του τεκμηρίου στον εκδότη:	https://mne2021.exordo.com/programme/presentation/476
Όνομα εκδήλωσης:	MNE 2021 Micro and Nano Engineering Conference
Τοποθεσία εκδήλωσης:	Turin, Italy
Ημ/νία έναρξης εκδήλωσης:	20/09/2021
Ημ/νία λήξης εκδήλωσης:	23/09/2021
Σημειώσεις:	This research is co-financed by Greece and the European Union (European Social Fund—ESF) through the Operational Program “Human Resources Development, Education and Lifelong Learning 2014– 2020” in the context of the project “HERON - "Interferometric system based on a 3D structured biochip: an application to quantitative determination of hazardous substances in food” (MIS 5047824)
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