Alessio Crescitelli took the master degree in Telecommunications Engineering in May 2005 at the University of Napoli "Federico II", discussing a thesis titled "Sensori in fibra ottica per l'analisi di sostanze liquide". In 2006, he won a fellowship for the XXI Ph.D. course at the University of Sannio, which has been focused on the development of bio-chemical sensors based on micro and nano-structured materials deposited onto optical fibers. This activity was carried out in collaboration with the IMCB-CNR of Napoli and with the Materials and Technology Unit of the research institute ENEA of Brindisi. In 2009, he received the Ph.D. Degree at the University of Sannio in "Information Engineering" with a thesis titled "Optoelectronic Technological Platforms Integrated with Micro and Nano-Structured Coatings for Chemical and Biological Sensing Applications". From 2011 to November 2013, Alessio Crescitelli worked as associate researcher at the Engineering Department of the University of Sannio. In addition, from 2012 to 2013, he worked as associate research at the Institute of Cybernetics "E. Caianello" CNR, Pozzuoli (NA), in order to realize and develop nano-photonic structures, via electron beam lithography. Since the beginning of the PhD course, Alessio Crescitelli has focused its research activities in the optoelectronic area for bio-chemical sensing applications and for the realization of photonic and plasmonic nano-structures on optical fiber and planar substrates. From December 2013 to date, Alessio Crescitelli works as researcher fellow at the IMM-CNR, in Napoli. Alessio Crescitelli has published more than 40 scientific papers published on international journals and conference proceedings. He has completed 4 book chapters, several patents and was co-editor of a Springer book enitled "Lab On Fiber Technology".
Abstract ‘Annurca’ apple, a southern Italian cultivar, is known for its reddening, taste and flav... more Abstract ‘Annurca’ apple, a southern Italian cultivar, is known for its reddening, taste and flavour among the other types of apples, and also for health promoting effects. The aim of this study is to evaluate the effect of a novel pre-treatment, by dipping in a solution containing trehalose, sodium chloride, sucrose, and of drying process conditions (temperature and time) on drying kinetics and quality attributes of dried apple slabs. Drying experiments were carried out by convective drying at temperatures of 50, 55, 60 and 65 °C at a constant air velocity of 2.3 m/s. Pre-treatment provided an increment of moisture loss, and a reduction of drying time and shrinkage at all temperatures. The combination of pre-treatment and drying at 65 °C assured the lowest colour changes, the best preservation of structure, as well as the less shrinkage, the higher rehydration capacity and the highest score for sensorial overall acceptability. On the contrary, the used pre-treatment combined with lower drying temperatures (50 and 55 °C) better preserve the antioxidant activity of apple slabs. In conclusion, the proposed solution enabled to reduce the processing time and better retain the quality attributes (i.e. physical, chemical, nutritional, sensorial) of dried apples slabs for their commercialization as snacks.
The steadily increasing demand for accurate analysis of vitamin D level, via measurement of its b... more The steadily increasing demand for accurate analysis of vitamin D level, via measurement of its best general marker, 25-hydroxyvitamin D (25(OH)D), pushes for the development of novel automated assays capable of working at very low concentrations. Here, we propose a plasmonic biosensor of 25(OH)D3 (calcifediol) based on surface-enhanced infrared absorption spectroscopy, which exploits the resonant coupling between plasmonic nanoantennas and vibrational excitation of small molecules. Specifically, our proposed platform features a large-area (several mm2) metasurface made of gold nanoantennas fabricated on a silicon substrate, comprising different macroregions (“pixels”) of area 500 × 500 µm2. In each pixel, the nanoantenna geometrical parameters are tuned so as to support localized surface plasmon resonances (and hence large field enhancements at the nanoscale) within different regions of the infrared spectrum. As a result, a single chip is capable of performing analysis from the reg...
Five onion landraces belonging toBianca di Pompeicv., cultivated in Campania region (Italy), were... more Five onion landraces belonging toBianca di Pompeicv., cultivated in Campania region (Italy), were characterized for their main quality parameters. The onion landraces were harvested at the end of the growth cycle corresponding to the ripening time and harvest month, respectively: February, March, April, May, and June. The total content of volatile compounds as well as the sulfur-containing compounds inAprilaticawas significantly (p≤0.05) higher than the other landraces investigated. The nutraceutical feature investigated through the total phenols, phenols profile, and antioxidant activity showed higher values for the samples harvested in spring months. High pungency values ranging from 9 to 14 μmol/g FW were found in all onion landraces investigated as enzymatically (alliinase) produced pyruvate (EPY). The organic acids profile (malic, citric, succinic, pyruvic, oxalic, ascorbic, and tartaric acids) highlighted malic and citric acids in higher amounts in all landraces. Fructose, glu...
Due to their increasing use in agriculture, the presence of pesticide residues in food and water ... more Due to their increasing use in agriculture, the presence of pesticide residues in food and water currently represents one of the major issues for the food safety. Among the pesticides, organophosphate and carbamate species are the most used, and their toxicity is mainly due to their inhibitory effect on acetylcholinesterase (AChE). For this reason, a monoenzymatic acetylcholinesterase impedimetric biosensor was developed in order to sensitively detect carbamate and organophosphate compounds with a very fast response. The working principle of the AChE biosensor exploits the capability of carbamate and organophosphate pesticides to form a stable complex with the enzyme, which causes an impedimetric change. The impedimetric biosensor showed a linearity between 5 and 170 ppb for carbamates and 2.5–170 ppb for or-ganophosphate compounds, with a reproducibility (RSD%) in-terelectrode equal to 4.8 and 3.1% for organophosphates and carbamates, respectively. Moreover, the common amperometric evaluation of AChE inhibition degree was correlated to the impedimetric changes of the electrode surface, showing a good correlation (R 2 = 0.99 for carbamates and R 2 = 0.98 for organophosphates) between the two methods. In contrast to amperometric evaluation that needs a response time of 20 min, impedimetric detection requires only 4 min. Finally, the impedimetric biosensor was used to measure carbaryl and dichlorvos spiked in different concentrations in tap water and lettuce samples, showing a recovery near to 100% for all concentrations and for both pesticides.
We report on the first demonstration of a proof-of-principle optical fiber 'meta-tip&... more We report on the first demonstration of a proof-of-principle optical fiber 'meta-tip', which integrates a phase-gradient plasmonic metasurface on the fiber tip. For illustration and validation purposes, we present numerical and experimental results pertaining to various prototypes implementing generalized forms of the Snell's transmission/reflection laws at near-infrared wavelengths. In particular, we demonstrate several examples of beam steering and coupling with surface waves, in fairly good agreement with theory. Our results constitute a first step toward the integration of unprecedented (metasurface-enabled) light-manipulation capabilities in optical-fiber technology. By further enriching the emergent 'lab-on-fiber' framework, this may pave the way for the widespread diffusion of optical metasurfaces in real-world applications to communications, signal processing, imaging and sensing.
Abstract ‘Annurca’ apple, a southern Italian cultivar, is known for its reddening, taste and flav... more Abstract ‘Annurca’ apple, a southern Italian cultivar, is known for its reddening, taste and flavour among the other types of apples, and also for health promoting effects. The aim of this study is to evaluate the effect of a novel pre-treatment, by dipping in a solution containing trehalose, sodium chloride, sucrose, and of drying process conditions (temperature and time) on drying kinetics and quality attributes of dried apple slabs. Drying experiments were carried out by convective drying at temperatures of 50, 55, 60 and 65 °C at a constant air velocity of 2.3 m/s. Pre-treatment provided an increment of moisture loss, and a reduction of drying time and shrinkage at all temperatures. The combination of pre-treatment and drying at 65 °C assured the lowest colour changes, the best preservation of structure, as well as the less shrinkage, the higher rehydration capacity and the highest score for sensorial overall acceptability. On the contrary, the used pre-treatment combined with lower drying temperatures (50 and 55 °C) better preserve the antioxidant activity of apple slabs. In conclusion, the proposed solution enabled to reduce the processing time and better retain the quality attributes (i.e. physical, chemical, nutritional, sensorial) of dried apples slabs for their commercialization as snacks.
The steadily increasing demand for accurate analysis of vitamin D level, via measurement of its b... more The steadily increasing demand for accurate analysis of vitamin D level, via measurement of its best general marker, 25-hydroxyvitamin D (25(OH)D), pushes for the development of novel automated assays capable of working at very low concentrations. Here, we propose a plasmonic biosensor of 25(OH)D3 (calcifediol) based on surface-enhanced infrared absorption spectroscopy, which exploits the resonant coupling between plasmonic nanoantennas and vibrational excitation of small molecules. Specifically, our proposed platform features a large-area (several mm2) metasurface made of gold nanoantennas fabricated on a silicon substrate, comprising different macroregions (“pixels”) of area 500 × 500 µm2. In each pixel, the nanoantenna geometrical parameters are tuned so as to support localized surface plasmon resonances (and hence large field enhancements at the nanoscale) within different regions of the infrared spectrum. As a result, a single chip is capable of performing analysis from the reg...
Five onion landraces belonging toBianca di Pompeicv., cultivated in Campania region (Italy), were... more Five onion landraces belonging toBianca di Pompeicv., cultivated in Campania region (Italy), were characterized for their main quality parameters. The onion landraces were harvested at the end of the growth cycle corresponding to the ripening time and harvest month, respectively: February, March, April, May, and June. The total content of volatile compounds as well as the sulfur-containing compounds inAprilaticawas significantly (p≤0.05) higher than the other landraces investigated. The nutraceutical feature investigated through the total phenols, phenols profile, and antioxidant activity showed higher values for the samples harvested in spring months. High pungency values ranging from 9 to 14 μmol/g FW were found in all onion landraces investigated as enzymatically (alliinase) produced pyruvate (EPY). The organic acids profile (malic, citric, succinic, pyruvic, oxalic, ascorbic, and tartaric acids) highlighted malic and citric acids in higher amounts in all landraces. Fructose, glu...
Due to their increasing use in agriculture, the presence of pesticide residues in food and water ... more Due to their increasing use in agriculture, the presence of pesticide residues in food and water currently represents one of the major issues for the food safety. Among the pesticides, organophosphate and carbamate species are the most used, and their toxicity is mainly due to their inhibitory effect on acetylcholinesterase (AChE). For this reason, a monoenzymatic acetylcholinesterase impedimetric biosensor was developed in order to sensitively detect carbamate and organophosphate compounds with a very fast response. The working principle of the AChE biosensor exploits the capability of carbamate and organophosphate pesticides to form a stable complex with the enzyme, which causes an impedimetric change. The impedimetric biosensor showed a linearity between 5 and 170 ppb for carbamates and 2.5–170 ppb for or-ganophosphate compounds, with a reproducibility (RSD%) in-terelectrode equal to 4.8 and 3.1% for organophosphates and carbamates, respectively. Moreover, the common amperometric evaluation of AChE inhibition degree was correlated to the impedimetric changes of the electrode surface, showing a good correlation (R 2 = 0.99 for carbamates and R 2 = 0.98 for organophosphates) between the two methods. In contrast to amperometric evaluation that needs a response time of 20 min, impedimetric detection requires only 4 min. Finally, the impedimetric biosensor was used to measure carbaryl and dichlorvos spiked in different concentrations in tap water and lettuce samples, showing a recovery near to 100% for all concentrations and for both pesticides.
We report on the first demonstration of a proof-of-principle optical fiber 'meta-tip&... more We report on the first demonstration of a proof-of-principle optical fiber 'meta-tip', which integrates a phase-gradient plasmonic metasurface on the fiber tip. For illustration and validation purposes, we present numerical and experimental results pertaining to various prototypes implementing generalized forms of the Snell's transmission/reflection laws at near-infrared wavelengths. In particular, we demonstrate several examples of beam steering and coupling with surface waves, in fairly good agreement with theory. Our results constitute a first step toward the integration of unprecedented (metasurface-enabled) light-manipulation capabilities in optical-fiber technology. By further enriching the emergent 'lab-on-fiber' framework, this may pave the way for the widespread diffusion of optical metasurfaces in real-world applications to communications, signal processing, imaging and sensing.
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Papers by Alessio Crescitelli