Matteo Agostini | Scuola Normale Superiore (original) (raw)

Papers by Matteo Agostini

Biosensors detect specific bio-analytes by generating a measurable signal from the interaction be... more Biosensors detect specific bio-analytes by generating a measurable signal from the interaction between the sensing element and the target molecule. Surface acoustic wave (SAW) biosensors offer unique advantages due to their high sensitivity, real-time response capability, and label-free detection. The typical SAW modes are the Rayleigh mode and the shear-horizontal mode. Both present pros and cons for biosensing applications and generally need different substrates and device geometries to be efficiently generated. This study investigates and characterizes ultra-high-frequency (UHF-) SAW resonator biosensors. It reveals the simultaneous presence of the two typical SAW modes, clearly separated in frequency, called slow and fast. The two modes are studied by numerical simulations and biosensing experiments with the glial-fibrillary-acidic-protein (GFAP) biomarker. The slow mode is generally more sensitive to changes in surface properties, such as temperature and mass changes, by a factor of about 1.4 with respect to the fast mode.

Advanced Functional Materials, Jul 7, 2022

Measles is one of the most infectious airborne viruses worldwide. With a basic reproduction rate ... more Measles is one of the most infectious airborne viruses worldwide. With a basic reproduction rate between 12–18, this virus is six times more infectious than the SARS‐CoV‐2 Alpha variant and similar to the SARS‐CoV‐2 Omicron variant. Even though a cheap and effective vaccine is available, measles is still common in developing countries. To date, sporadic outbreaks are also reported in developed countries, primarily due to non‐vaccinated people. This work presents a point‐of‐care (POC) biosensing device capable of detecting measles virions (MV) in human saliva. The device is a surface‐acoustic‐wave (SAW) based lab‐on‐a‐chip (LOC), smaller than a €1‐cent coin, in which SAWs are used both for sensing and fluid recirculation. The biosensing detection performance of this system is tested and device sensitivity and selectivity are assessed. The SAW‐LOC with MV loaded in healthy, whole human saliva is finally validated. The experimental results also highlight a crucial aspect of the biosensing process: the interactions between probing and target species during incubation with or without fluid mixing. The presented findings are promising for realizing a POC platform for measles diagnosis and may serve as a guideline for designing new microfluidics‐based biosensing systems.

IEEE Sensors Journal, Apr 15, 2021

This paper shows the optical photoresponse in the IR-Vis-UV range of a AlN-based piezoelectric su... more This paper shows the optical photoresponse in the IR-Vis-UV range of a AlN-based piezoelectric surface acoustic wave (SAW) delay-line device. The piezoelectric aluminum nitride (AlN) thin film has been sputtered on both silicon rigid substrate and flexible polyethylene naphthalate (PEN) substrate. Both devices have been investigated in their electroacoustic response, by measuring the transfer function S21 and by laser Doppler vibrometer characterization. The silicon based SAW devices, stimulated by the IR-Vis-UV light, are strongly affected in the out-of-band insertion loss due to the photovoltaic effect. A mathematical model has been implemented to correlate the out-of-band loss with the material’s electrical admittance change. In contrast PEN based SAW devices, due to the polymeric nature of the substrate, did not show any variation in the out-of-band loss. Moreover, when exposed to UV light, a frequency downshift of the Rayleigh and Lamb resonances modes have been observed in all the devices, due screening of the photoinduced electrons in the AlN piezoelectric layer which induces an acoustic wave velocity reduction. To the best of our knowledge, this is the first photoresponse study exploiting SAW in the range IR-Vis-UV, suggesting a new detection mode of UV light by a flexible AlN based SAW device. Further development of these devices can lead to a new class of light sensors from UV to IR, based on remote SAW devices.

Sensors and Actuators B-chemical, Mar 1, 2023

World Academy of Science, Engineering and Technology, International Journal of Bioengineering and Life Sciences, Jun 9, 2016

Acta horticulturae, Jun 1, 2023

Frontiers in Molecular Biosciences, Nov 28, 2022

Nanotechnology, Jun 22, 2021

Surface acoustic wave (SAW) devices offer many benefits in chemistry and biomedicine, enabling pr... more Surface acoustic wave (SAW) devices offer many benefits in chemistry and biomedicine, enabling precise manipulation of micro-droplets, mixing of liquids by acoustic streaming and pumping of liquids in enclosed channels, while presenting a cost-effective and easy fabrication and integration with electronic devices. In this work, we present microfluidic devices which use graphene-based interdigital transducers (IDTs) to generate SAWs with a frequency of 100 MHz and an amplitude of up to 200 pm, which allow us to manipulate microparticle solutions by acoustic streaming. Due to the negligible mass loading of the piezoelectric surface by graphene, the SAWs generated by these devices have no frequency shift, typically observed when metal IDTs are used.

Micromachines

Biosensors based on surface acoustic waves (SAWs) offer unique advantages due to their high sensi... more Biosensors based on surface acoustic waves (SAWs) offer unique advantages due to their high sensitivity, real-time response capability, and label-free detection. The typical SAW modes are the Rayleigh mode and the shear-horizontal mode. Both present pros and cons for biosensing applications and generally need different substrates and device geometries to be efficiently generated. This study investigates and characterizes SAW resonator biosensors on lithium niobate in terms of modes generated and biosensing performance. It reveals the simultaneous presence of two typical SAW modes, the first around 1.6 GHz and the second around 1.9 GHz, differently polarized and clearly separated in frequency, which we refer to as slow and fast modes. The two modes are studied by numerical simulations and biosensing experiments with the glial-fibrillary-acidic-protein (GFAP) biomarker. The slow mode is generally more sensitive to changes in surface properties, such as temperature and mass changes, by...

Biosensors

Enzyme detection in liquid samples is a complex laboratory procedure, based on assays that are ge... more Enzyme detection in liquid samples is a complex laboratory procedure, based on assays that are generally time- and cost-consuming, and require specialized personnel. Surface acoustic wave sensors can be used for this application, overcoming the cited limitations. To give our contribution, in this work we present the bottom-up development of a surface acoustic wave biosensor to detect active α-glycosidase in aqueous solutions. Our device, optimized to work at an ultra-high frequency (around 740 MHz), is functionalized with a newly synthesized probe 7-mercapto-1-eptyl-D-maltoside, bringing one maltoside terminal moiety. The probe is designed ad hoc for this application and tested in-cuvette to analyze the enzymatic conversion kinetics at different times, temperatures and enzyme concentrations. Preliminary data are used to optimize the detection protocol with the SAW device. In around 60 min, the SAW device is able to detect the enzymatic conversion of the maltoside unit into glucose i...

Nanomaterials, 2022

Polyphenols are a family of compounds present in grapes, musts, and wines. Their dosage is associ... more Polyphenols are a family of compounds present in grapes, musts, and wines. Their dosage is associated with the grape ripening, correct must fermentation, and final wine properties. Owing to their anti-inflammatory properties, they are also relevant for health applications. To date, such compounds are detected mainly via standard chemical analysis, which is costly for constant monitoring and requires a specialized laboratory. Cheap and portable sensors would be desirable to reduce costs and speed up measurements. This paper illustrates the development of strategies for sensor surface chemical functionalization for polyphenol detection. We perform measurements by using a commercial quartz crystal microbalance with dissipation monitoring apparatus. Chemical functionalizations are based on proteins (bovine serum albumin and gelatin type A) or customized peptides derived from istatine-5 and murine salivary protein-5. Commercial oenological additives containing pure gallic tannins or proa...

Nanotechnology, 2021

Surface acoustic waves (SAWs) have the potential to become the basis for a wide gamut of lab-on-a... more Surface acoustic waves (SAWs) have the potential to become the basis for a wide gamut of lab-on-a-chips (LoCs). These mechanical waves are among the most promising physics that can be exploited for fulfilling all the requirements of commercially appealing devices that aim to replace–or help–laboratory facilities. These requirements are low processing cost of the devices, scalable production, controllable physics, large flexibility of tasks to perform, easy device miniaturization. To date, SAWs are among the small set of technologies able to both manipulate and analyze biological liquids with high performance. Therefore, they address the main needs of microfluidics and biosensing. To this purpose, the use of high-frequency SAWs is key. In the ultra-high-frequency regime (UHF, 300 MHz—3 GHz) SAWs exhibit large sensitivities to molecule adsorption and unparalleled fluid manipulation capabilities, together with overall device miniaturization. The UHF-SAW technology is expected to be the...

Biosensors and Bioelectronics, 2021

APL Materials, 2019

In order to properly manipulate liquids into microfluidic networks, an accurate sealing of the de... more In order to properly manipulate liquids into microfluidic networks, an accurate sealing of the device is of paramount importance. Polydimethylsiloxane (PDMS) is ubiquitously used for fabricating microfluidic components, owing to its low cost, easy and fast fabrication, and optical transparency. However, PDMS is characterized by low surface energy, making its bonding to many substrates not trivial. Here is presented a versatile technique for PDMS microchannel bonding on untreated plastic and metal surfaces. First, the PDMS surface is functionalized with (3-aminopropyl) triethoxysilane (APTES) for further cross-linking with epoxy groups. Then, the PDMS-APTES surface is coated with Norland Optical Adhesive 74 (NOA74). Finally, the PDMS-APTES-NOA74 is put in contact with the target material and the glue is cured under a UV light. In order to characterize the bonding strength, a complete PDMS-on-gold microfluidic device is fabricated and tested with increasing injection pressures. Differ...

Sensors and Actuators B: Chemical, 2017

Lab on a Chip, 2016

A novel, surface plasmon resonance phase-interrogation based microfluidic biosensor in which surf... more A novel, surface plasmon resonance phase-interrogation based microfluidic biosensor in which surface acoustic wave-driven mixing accelerates molecule binding kinetics up to 84% of the reaction time is presented.

Advanced Functional Materials, 2015