Diego Pallarola

• PhD in Chemistry
• Head of Department at Nanosystems Institute

Electrochemical impedance spectroscopy (EIS) is a suitable analytical technique to detect interfacial phenomena and analyte binding at electrode surfaces. In contrast to metallic electrodes, carbon‐based electrodes are more suited due to the low cost and the availability of more versatile methods for chemical functionalization. For (bio) sensing, o...

Soft substrates are interesting for a range of applications from mimicking cellular micro-environment to implants. Conductive electrodes on soft substrates open a broad spectrum of possibilities such as electrical and electrochemical sensing coupled with the flexibility, elasticity and transparency of the underlying substrate. Single layer graphene...

Graphene oxide has been widely deployed in electrical sensors for monitoring physical, chemical, and biological processes. The presence of abundant oxygen functional groups makes it an ideal substrate for integrating biological functional units to assemblies. However, the introduction of this type of defects on the surface of graphene has a deleter...

The incorporation of sophisticated capabilities within microfluidic devices often requires the assembly of different layers in a correct arrangement. For example, when it is desired to include electrodes inside microfluidic channels or to create 3D microfluidic structures. However, the alignment between different substrates at the microscale requir...

Several fields of applications require a reliable characterization of the photothermal response and heat dissipation of nanoscopic systems, which remains a challenging task both for modeling and experimental measurements. Here, we present a new implementation of anti-Stokes thermometry that enables the in situ photothermal characterization of indiv...

Cells interact with their microenvironment by constantly sensing mechanical and chemical cues converting them into biochemical signals. These processes allow cells to respond and adapt to changes in their environment, and are crucial for most cellular functions. Understanding the mechanism underlying this complex interplay at the cell-matrix interf...

Several fields of applications require a reliable characterization of the photothermal response and heat dissipation of nanoscopic systems, which remains a challenging task both for modeling and experimental measurements. Here, we present an implementation of anti-Stokes thermometry that enables the in situ photothermal characterization of individu...

Existen antecedentes sobre la utilización de óxido de grafeno (GO) como plataforma para la funcionalización con diversos compuestos. Recientemente se han utilizado nanofibras de plata (AgNWs) sobre GO para el desarrollo de biosensores. La presencia de diversos grupos funcionales químicos, a través de los cuales pueden incorporarse de manera control...

The formation of new types of sensitive conductive surfaces for the detection and transduction of cell-extracellular matrix recognition events in a real time, label-free manner is of great interest in the field of biomedical research. To study molecularly defined cell functions, biologically inspired materials that mimic the nanoscale order of extr...

In this study we investigate the impact of ligand presentation by various molecular spacers on integrin-based focal adhesion formation. Gold nanoparticles (AuNPs) arranged in hexagonal patterns were biofunctionalized with the same ligand head group, cyclic Arg-Gly-Asp [c(-RGDfX-)], but with different molecular spacers, each of which couples the hea...

For quite a while, scientists have resorted to colloidal synthesis to mimic complex structural and functional materials found in Nature. In particular, within the past few years, the synthesis of suprastructures with novel properties that emerge from the coupling of diverse nanoscale functional units has defined new boundaries in materials science....

We report the recognition-driven assembly of self-limiting protein nanoparticles displaying enzymatic activity. Solution self-assembly of concanavalin A lectin and glycoenzyme glucose oxidase leads to the spontaneous formation biocolloids with well-defined dimensions, narrow size distribution and remarkable stability. These biocolloids successfully...

Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redox-active polyelectrolyte–surfactant complex containing [Os(bpy)2Clpy]2+ (bpy=2,2′-bipyridine, py= pyridine) as the redox centers a...

Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redoxactive polyelectrolyte surfactant complex containing [Os(bpy)(2)Clpy](2+) (bpy=2,2'-bipyridine, py= pyridine) as the redox center...

The interaction of specific surface receptors of the integrin family with different extracellular matrix‐based ligands is of utmost importance for the cellular adhesion process. A ligand consists of an integrin‐binding group, here cyclic RGDfX, a spacer molecule that lifts the integrin‐binding group from the surface and a surface anchoring group. c...

A plasmonic sensor composed of a vertically aligned gold nanowire array was fabricated and employed for the optical detection of protein adsorption induced by an electric field.

Due to their ability to confer key functions of the native extracellular matrix (ECM), poly(ethylene glycol) (PEG)-based and PEG-modified materials have been extensively used as biocompatible and biofunctionalized substrate systems to study the influence of environmental parameters on cell adhesion in vitro. Given wide-ranging recent evidence that...

Integrins are the major class of cell adhesion proteins. Their interaction with different ligands of the extracellular matrix (ECM) is diverse. To get more insight in these interactions, selective artificial ligands endowed with a defined activity/selectivity profile are necessary. Herein, we present a library of cyclic pentapeptides, based on our...

This work describes the synergistic combination of ionic self-assembly and recognition-directed assembly with the aim of creating highly functional bioelectrochemical interfaces compatible with the supramolecular design of a wide variety of biosensing platforms. A recently synthesized glycopolyelectrolyte constituted of polyallylamine bearing redox...

This work explores the synergistic combination of ionic self-assembly and recognition-directed assembly for the modification of electrode surfaces with redox glycoenzymes on the basis of electroactive glycopolyelectrolyte-surfactant complexes.

The development of soft bioelectronic interfaces with accurate compositional and topological control of the supramolecular architecture attracts intense interest in the fast-growing field of bioelectronics and biosensing. The present study explores the recognition-driven layer-by-layer assembly of glycoenzymes onto electrode surfaces. The design of...

This chapter presents a conjugation method for coupling probes bearing hydrazine or primary amino groups to a smooth(S)-form lipopolysaccharide (LPS). LPS is modified by the activation of the hydroxyl groups present in its O-antigen moiety with cyanogen bromide in aqueous acetone. The method yields conjugates with good labeling ratios, preserving t...

This chapter presents a conjugation method for coupling probes bearing hydrazine or primary amino groups to a lipopolysaccharide (LPS). LPS is modified by the activation of the hydroxyl groups present in its O-antigen moiety with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP). The method yields conjugates with good labeling ratios, pres...

The integration of redox glycoenzymes on conductive supports plays a pivotal role in the successful design of bioelectronic platforms, including, among others, biosensors or biofuel cells. Recognition-directed biosupramolecular assembly emerged as an interesting and attractive alternative due to its simplicity and versatility, without introducing c...

The convergence of chemistry, biology, and materials science has paved the way to the emergence of hybrid nanobuilding blocks that incorporate the highly selective recognition properties of biomolecules, with the tailorable functional capabilities of inorganic molecules. In this work, we describe for the first time the decoration of concanavalin A...

There is a growing quest for the construction of functional supramolecular architectures to efficiently translate (bio)chemical events into easily measurable signals. This interest originates from its inherent scientific relevance as well as from their potential applications in the ever-flourishing areas of bioelectronics and biosensing. Herein, we...

Endotoxins, also referred to as pyrogens, are lipopolysaccharides (LPS) present in the outer membrane of Gram-negative bacteria, and represent one of the most dangerous microbiological contaminants in water for hemodialysis and intravenous infusion. A method is presented for the simultaneous detection of endotoxins and other bacterial lysis contami...

The activation of a lipopolysaccharide (LPS) with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) in the presence of a surfactant allows an efficient conjugation with dansyl hydrazine or horseradish peroxidase (HRP) in an aqueous medium maintaining its biological activity. In order to promote the reaction a series of amphiphilic compound...

A conjugation method for coupling probes bearing hydrazine or primary amino groups to a lipopolysaccharide (LPS) is described. LPS is modified through the hydroxyl groups present in its O-antigen moiety by activation with cyanogen bromide in aqueous acetone using triethylamine to enhance the electrophilicity of CNBr. The method yields conjugates wi...

A biotin-lipopolysaccharide (biotin-LPS) conjugate was synthesized from LPS smooth from Salmonella minnesota, yielding a conjugate with a biotin/LPS ratio equal to 1:1 and endotoxic activity of 0.08 EU ng(-1). The conjugate was used in an amperometric competitive assay to determine endotoxins with endotoxin-neutralizing protein (ENP) as the recogni...

In this work, two well known polymers, carboxymethyl dextran and poly(ethyleneglycol), are used for easily producing a platform for electrochemical affinity assays, avoiding nonspecific adsorption of proteins. In this way, modified electrode surfaces able to bind a recognition agent are constructed through simple and reliable reactions. 24 and 70 K...