Omar Azzaroni

• PhD
• Head of Department at INIFTA-CONICET-UNLP

We developed an arginine-responsive biosensor by integrating cascade enzymatic reactions into nanochannels functionalized with weak polyelectrolytes, which serve as "reactive signal amplifiers." This approach enhances device performance and broadens the...

Sequential deposition of polymer layers of very diverse characteristics has been applied to produce nanoassemblies of well‐controlled thickness and physico‐chemical properties. While conventional layer‐by‐layer approaches are based on the sequential deposition of distinct, mutually interacting materials, nanoassemblies formed by a single, unique po...

Herein, we present a novel approach to quantify ferritin based on the integration of an Enzyme-Linked Immunosorbent Assay (ELISA) protocol on a Graphene Field-Effect Transistor (gFET) for bioelectronic immunosensing. The G-ELISA strategy takes advantage of the gFET inherent capability of detecting pH changes for the amplification of ferritin detect...

Chronic kidney disease (CKD) is a significant global health concern, impacting over 10% of the world population. Despite advances in home‐based treatments, CKD diagnosis and monitoring remain centralized in large laboratories. This work reports on the development of a Graphene‐based Lab‐On‐a‐Chip (G‐LOC) for the self‐testing of multiple renal funct...

We present the construction of an organic electrochemical transistor (OECT) based on poly(3,4-ethylendioxythiophene, PEDOT) and polyallylamine (PAH) and its evaluation as a bioelectronic platform for urease integration and urea sensing. The OECT channel was fabricated in a one-step procedure using chemical polymerization. Then, urease was immobiliz...

Solid-state nanochannels (SSNs) have emerged as promising platforms for controlling ionic transport at the nanoscale. SSNs are highly versatile, and this feature can be enhanced through their combination with porous materials such as Metal−Organic Frameworks (MOF). By selection of specific building blocks and experimental conditions, different MOF...

In this study, the transport of salt with moderate solubility through bioinspired solid-state nanochannels was comprehensively investigated. For this purpose, bullet-shaped channels were fabricated and exposed to KClO4, a monovalent...

Metal–organic frameworks (MOFs) have settled in the scientific community over the last decades as versatile materials with several applications. Among those, zeolitic imidazolate framework 8 (ZIF-8) is a well-known MOF that has been applied in various and diverse fields, from drug-delivery platforms to microelectronics. However, the complex role pl...

Chronic kidney disease is one of the major health issues worldwide. However, diagnosis is now highly centralized in large laboratories, resulting in low access to patient monitoring and poor personalized treatments. This work reports the development of a graphene-based lab-on-a-chip (G-LOC) for the digital testing of renal function biomarkers in se...

Nanofluidic field-effect transistors for tailored transport and bio-inspired functionalities: solid-state nanochannels can be smartly tuned by external potentials to induce open/closed states or promote ion selectivity in the same way as biological ion channels.

Supercapacitors are devices that bridge the gap between traditional capacitors and rechargeable batteries, offering exceptional energy storage capabilities, rapid charge/discharge rates, long cycle life, and environmental friendliness. This study explores the development of neutral-aqueous supercapacitor materials using conductive polymers, with a...

Sub-micrometre thin alternate bilayers of materials with appropriate refractive index contrast are widely used for the assembly of sensors based on the stimuli-responsiveness of such 1D photonic crystals (PC). A...

We studied ionic transport properties of UiO-66 metal-organic framework-modified solid-state nanochannels (MOF@SSNs) embedded in polyethylene terephthalate (PET) membranes, focusing on the effect of calcium ions from chloride salt (CaCl2) acting...

Neurotransmitters are endogenous chemical messengers that play crucial roles in the transmission, enhancement and conversion of specific signals between neurons and other cells and are considered biomarkers of neurodegenerative diseases.[1] Neurodegenerative diseases cause progressive loss of cognitive and/or motor function and, as life expectancy...

Organic electrochemical transistors (OECTs) are important devices for the development of flexible and wearable sensors due to their flexibility, low power consumption, sensitivity, selectivity, ease of fabrication, and compatibility with other flexible materials. These features enable the creation of comfortable, versatile, and efficient portable d...

The layer-by-layer (LbL) technique has been proven to be one of the most versatile approaches in order to fabricate functional nanofilms. The use of simple and inexpensive procedures as well as the possibility to incorporate a very wide range of materials through different interactions have driven its application in a wide range of fields. On the o...

This work reports the phase behavior and electro-chemical properties of liquid coacervates made of ferricyanide and poly(ethylenimine). In contrast to the typical polyanion/polycation pairs used in liquid coacervates, the ferricyanide/poly-(ethylenimine) system is highly asymmetric because poly-(ethylenimine) has approximately 170 charges per molec...

Metal-Organic Frameworks (MOFs) have settled in the scientific community over the last decades as versatile materials with several applications. Among those, Zeolitic Imidazolate Framework 8 (ZIF-8) is a well-known MOF that has been applied in various and diverse fields, from drug-delivery platforms to microelectronics. However, the complex role pl...

The assembly of polyelectrolytes and biomacromolecules (proteins, DNA) has attracted great attention in several fields related to medicine, molecular biology, and clinical chemistry. Here, a quick and easy multicomponent self-assembly is used to unite two species with the same charge to form an electroactive polyamine-enzyme assembly. Phosphate ion...

The complexation of polyelectrolytes with other oppositely charged structures gives rise to a great variety of functional materials with potential applications in a wide spectrum of technological fields. Depending on the assembly conditions, polyelectrolyte complexes can acquire different macroscopic configurations such as dense precipitates, nanos...

The fabrication of efficient organic electrochemical transistors (OECTs)-based biosensors requires the design of biocompatible interfaces for the immobilization of biorecognition elements, as well as the development of robust channel materials to enable the transduction of the biochemical event into a reliable electrical signal. In this work, PEDOT...

"Clickable" organic electrochemical transistors (OECTs) allow the reliable and straightforward functionalization of electronic devices through the well-known click chemistry toolbox. In this work, we study various aspects of the click chemistry-based interface engineering of "clickable" OECTs. First, different channel architectures are investigated...

[This corrects the article DOI: 10.1021/jacsau.2c00515.].

Nanofluidic channels in which the ionic transport can be modulated by the application of an external voltage to the nanochannel walls have been described as nanofluidic field effect transistors (nFETs) because of their analogy with electrolyte-gated field effect transistors. The creation of nFETs is attracting increasing attention due to the possib...

Nanopores have been applied in the development of artificial biocatalytic systems, controlled drug delivery, and solid-state nanopore sensing devices. The interaction of biomacromolecules, sensitive to their microenvironment, with surfaces show...

Multiphase aqueous-organic systems where a bicontinuous phase is in equilibrium with an excess organic and aqueous phase find various applications in industry. These systems─also known as Winsor III─are complex not only for the different phases that develop therein but also because they are multicomponent systems. In this work, we explore for the f...

Recent developments surrounding the oxygen reduction reaction (ORR) focus on low‐cost alternatives to materials used in traditional electrodes, e. g. Pt. To accumulate competitive advantages, these non‐traditional electrodes often consist of multiple functional coating layers. Considering that each layer can potentially alter the reaction mechanism...

Interfacing the surface of an organic semiconductor with biological elements is a central quest when it comes to the development of efficient organic bioelectronic devices. Here, we present the first example of “clickable” organic electrochemical transistors (OECTs). The synthesis and characterization of an azide-derivatized EDOT monomer (azidometh...

The use of track-etched membranes allows further fine-tuning of transport regimes and thus enables their use in (bio)sensing and energy harvesting applications, among others. Recently, metal-organic frameworks (MOFs) have been combined with such membranes to further increase their potential. Herein, the creation of a single track-etched nanochannel...

The manipulation and understanding of molecular transport across functionalized nanopores will take us closer to mimicking biological membranes and thus to design high-performance permselective separation systems. In this work, Surface-initiated atom transfer radical polymerization (SI-ATRP) of (2-methacryloyloxy)-ethyltrimethylammonium chloride (M...

The interaction between polyamines and phosphate species is found in a wide range of biological and abiotic systems, yielding crucial consequences that range from the formation of supramolecular colloids to structure determination. In this work, the occurrence of phosphate-amino interactions is evidenced from changes in the electronic response of g...

Acetylcholinesterase-modified nanochannels are proposed as reliable and reproducible nanofluidic sensors for highly sensitive detection of acetylcholine. The operation mechanism relies on the use of weak polyelectrolytes as "chemical amplifiers" that adjust/reconfigure the nanochannel surface charge in the presence of local pH changes induced by th...

Katsuhiko Ariga and Omar Azzaroni introduce the Nanoscale and Nanoscale Advances themed collection on the design and function of materials nanoarchitectonics.

Graphene field-effect transistors (gFETs) are promising tools for the development of precise and affordable techniques for the study of molecular binding kinetics, crucial in applications such as biomolecule therapies, drug discovery, and medical diagnostics. Nevertheless, determining the reliability and modeling the gFET signal for the monitoring...

Conjugated polymers (CP) constitute nonexpensive stable building blocks for the construction of a variety of electrochemically active complex materials. Due to their particular electronic structure, they present as light metal-free conducting materials that can be prepared using soft chemical methods. This makes them immensely suitable for electroc...

The biofunctionalization of graphene field-effect transistors (GFETs) through vinylsulfonated-polyethyleneimine nanoscaffold is presented for enhanced biosensing of severe acute respiratory-related coronavirus 2 (SARS-CoV-2) spike protein and human ferritin, two targets of great importance for the rapid diagnostic and monitoring of individuals with...

The concept of nanoarchitechtonics was introduced to describe the correct manipulation of nanoscale materials in the creation of nano-devices and applications. Nanoarchitectonics has begun to spread into many fields including nanostructured materials synthesis, supramolecular assembly, nanoscale structural fabrications, materials hybridizations, ma...

The concept of nanoarchitechtonics was introduced to describe the correct manipulation of nanoscale materials in the creation of nano-devices and applications. Nanoarchitectonics has begun to spread into many fields including nanostructured materials synthesis, supramolecular assembly, nanoscale structural fabrications, materials hybridizations, ma...

We hereby report on the thermodynamic and kinetic aspects of ZIF-8 MOF synthesis when performed using methanolic solutions of precursors and 3-mercaptopropionic acid (MPA) acting as a chemical modifying agent. MPA is of great interest as it allows us to gain control over the surface chemistry, shape, and size of colloidal porous nanounits formed. I...

During the past decade, solid-state nanopores and nanochannels (SSNs) have emerged as a new class of devices for the creation of nanofluidic platforms with diverse applications. In particular, the precise control of ion transport achieved by SSNs paved the way to the development of specific and efficient biological and chemical iontronic sensors wi...

In celebration of the excellence and breadth of Latin American research achievements across the chemical sciences, we are delighted to present an introduction to the themed collection, Celebrating Latin American talent in chemistry.

The ionic screening and the response of non-specific molecules are great challenges of biosensors based on field-effect transistors (FETs). In this work, we report the construction of graphene based transistors modified with mesoporous silica thin films (MTF-GFETs) and the unique (bio)sensing properties that arise from their synergy. The developed...

It is well known that graphene field-effect transistors (gFETs) are sensitive to changes in the pH of the solution in which they are immersed, and this phenomenon allows the (bio)sensing of different analytes. 1,2 In this work, we study a possible treatment to increase the pH sensitivity of gFETs. Under the hypothesis that gFETs with a greater oxid...

Polymer coating on fluorescent silica nanoparticles enables to tailor made nanocomposite with unique tunable properties. Combining the emission of a fluorescent probe and the surface chemistry of a polymer shell a wide range of applications can be cover. The changing in the conformation of polymer chains enables to modify the hydrophilicity of the...

We introduce a new approach for glucose oxidase (GOx) immobilization on graphene field-effect transistors (gFETs) to fabricate highly sensitive glucose sensors. The strategy relies on the electropolymerization of a layer of the copolymer polyIJ3-amino-benzylamine-co-aniline) (PABA) on graphene-based transistors. The synthesized polymer film provides...

We present a strategy for the integration of three building blocks in a functional interfacial nanoarchitecture in order to fabricate composite films with improved features towards the electrochemical oxygen reduction reaction (ORR). Firstly, multilayer films of polyethyleneimine (PEI) and poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (...

Advanced nanostructured membranes with high ion flux and selectivity bring new opportunities for generating clean energy by exploiting the osmotic pressure difference between water sources of different salinities.

Viral infections are a major global health issue, but no current method allows rapid, direct, and ultrasensitive quantification of intact viruses with the ability to inform infectivity, causing misdiagnoses and spread of the viruses. Here, we report a method for direct detection and differentiation of infectious from noninfectious human adenovirus...

Biomimetic solid-state nanochannels enable new modalities for biosensing. In the last decade, these nanofluidic architectures have been widely studied due to their rapid and sensitive detection capabilities. Developing nanofluidic sensors with great ability to sense ions, small biomolecules, and biological macromolecules requires the combination of...

Organic bioelectronics involves the connection of organic semiconductors with living organisms, organs, tissues, cells, membranes, proteins, and even small molecules. In recent years, this field has received great interest due to the development of all kinds of devices architectures, enabling the detection of several relevant biomarkers, the stimul...

Recently, much scientific effort has been centered on the control of the ionic transport properties of solid state nanochannels and the rational design and integration of chemical systems to induce changes in the ionic transport by means of interactions with selected target molecules. Here, we report the fabrication of a novel nanofluidic device ba...

The construction of organic electrochemical transistors (OECTs) using poly(3,4‐ethylenedioxythiophene):tosylate and polyallylamine hydrochloride composites as conducting channel material is presented. The regulation of the polyelectrolyte‐to‐conducting polymer proportion allows one to easily tune both electronic and ionic characteristics of the tra...

Redox mediators are pivotal players in the electron transfer process between enzymes and electrodes. We present an alternative approach for redox mediation based on branched polyethyleneimine (BPEI) modified with an osmium complex. This redox polyelectrolyte is crosslinked with phosphate to produce colloidal particles with a diameter of ca. 1 μm, w...

The flux of cells at the cell colony border region is expected to be controlled by ridge-patterned substrates, and the cell colony displacement velocity influenced by the orientation of the ridges with respect to the colony contour. In this work patterns with regularly separated ridges are employed to fabricate tilted initially quasi-linear colony...

We have explored the use of two different iron-based porous materials for arsenic uptake from neutral pH aqueous solutions. Both materials are reminiscent of a material known as MIL-100(Fe), a Metal Organic Framework (MOF) built upon the coordination of Fe(III) ions with trimesate organic linkers (benzene tricarboxylic acid). Aside from the proverb...

Tunable hardness materials have shown fascinating properties, which place them as potential materials for use in different technological fields. This work deals with the bulk and confined synthesis of copolymers based on butyl methacrylate and 2-hydroxyethyl acrylate (HEA), prepared by atom transfer radical copolymerization in the entire compositio...

Colloidal suspensions of Zn-based ZIF-8 metal−organic framework (MOF) particles were synthesized (both micrometer μ-ZIF-8 and nanometer n-ZIF-8-sized, respectively). Postsynthetic modification was carried using 2-amino-ethanethiol (cysteamine or Cys), a thiol-bearing monodentate ligand, and particles obtained were employed for the assembly of films...

This work reports on a novel and versatile approach to control the structure of metal–organic framework (MOFs) films by using polymeric brushes as 3D primers, suitable for triggering heterogeneous MOF nucleation. As a proof‐of‐concept, this work explores the use of poly(1‐vinylimidazole) brushes primer obtained via surface‐initiated atom transfer r...

ZIF‐8 (based on Zn and 2‐methylimidazole) MOF film growth can be controlled by using SI‐ATRP‐synthesized polymeric brushes as 3D primers. This strategy relies on the inclusion of chemical moieties in the brush, which are compatible with MOF chemical structure. According to such criteria, Poly(1‐vinylimidazole) brushes with increasingly higher graft...

During the last years, much scientific effort has been focused on the control of the ionic transport properties of solid state nanochannels and the rational integration of chemical systems to induce changes in the ionic transport by interaction with selected target molecules for (bio)sensing purposes. In this work, we present the construction and f...

The Cover Feature shows a 2D hexagonal mesostructured electroactive film obtained through layer‐by‐layer assembly of (ferrocenylmethyl)hexadecyldimethylammonium bromide, a redox surfactant, and poly(acrylic acid). The picture also includes an experimental GISAXS pattern of the mesostructured film. By using ferrocene‐appended surfactants as structur...