Valerii Myndrul

Bio: Valerii Myndrul is an academic researcher from Adam Mickiewicz University in Poznań. The author has contributed to research in topics: Atomic layer deposition & Biosensor. The author has an hindex of 6, co-authored 9 publications receiving 129 citations. Previous affiliations of Valerii Myndrul include ODESSA.

Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications.

Abstract: In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a "shoulder-shape" emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphologies

Abstract: Zinc oxide (ZnO) is a multifunctional material due to its exceptional physicochemical properties and broad usefulness. The special properties resulting from the reduction of the material size from the macro scale to the nano scale has made the application of ZnO nanomaterials (ZnO NMs) more popular in numerous consumer products. In recent years, particular attention has been drawn to the development of various methods of ZnO NMs synthesis, which above all meet the requirements of the green chemistry approach. The application of the microwave heating technology when obtaining ZnO NMs enables the development of new methods of syntheses, which are characterised by, among others, the possibility to control the properties, repeatability, reproducibility, short synthesis duration, low price, purity, and fulfilment of the eco-friendly approach criterion. The dynamic development of materials engineering is the reason why it is necessary to obtain ZnO NMs with strictly defined properties. The present review aims to discuss the state of the art regarding the microwave synthesis of undoped and doped ZnO NMs. The first part of the review presents the properties of ZnO and new applications of ZnO NMs. Subsequently, the properties of microwave heating are discussed and compared with conventional heating and areas of application are presented. The final part of the paper presents reactants, parameters of processes, and the morphology of products, with a division of the microwave synthesis of ZnO NMs into three primary groups, namely hydrothermal, solvothermal, and hybrid methods.

Porous Silicon-Based Photonic Biosensors: Current Status and Emerging Applications

Abstract: Since its first demonstration as a promising material for molecular detection two decades ago, porous silicon (PSi) has become a commercially viable optical biosensor platform attracting sustained research interest. Progress in both fundamental understanding and diverse application areas has occurred. In particular, new approaches for biosensor design, new implementations of PSi as a host matrix for synergistic materials that enable alternate biosensor readout approaches and signal enhancement, new methods to reliably achieve higher detection sensitivity, and new emphases on detection of molecules in complex media, integration with microfluidics for sample handling, and multiplexed detection capabilities have been reported. In all cases, the extremely high internal surface area of PSi, the ease in modifying the surface chemistry of PSi, and the straightforward fabrication of PSi films are key advantages for PSi biosensors. This review focuses on advances in PSi optical biosensors achieved over the past three years.

Application of Gold Nanoparticle to Plasmonic Biosensors.

Abstract: Gold nanoparticles (GNPs) have been widely utilized to develop various biosensors for molecular diagnosis, as they can be easily functionalized and exhibit unique optical properties explained by plasmonic effects. These unique optical properties of GNPs allow the expression of an intense color under light that can be tuned by altering their size, shape, composition, and coupling with other plasmonic nanoparticles. Additionally, they can also enhance other optical signals, such as fluorescence and Raman scattering, making them suitable for biosensor development. In this review, we provide a detailed discussion of the currently developed biosensors based on the aforementioned unique optical features of GNPs. Mainly, we focus on four different plasmonic biosensing methods, including localized surface plasmon resonance (LSPR), surface-enhanced Raman spectroscopy (SERS), fluorescence enhancement, and quenching caused by plasmon and colorimetry changes based on the coupling of GNPs. We believe that the topics discussed here are useful and able to provide a guideline in the development of novel GNP-based biosensors in the future.

A novel electrochemical aflatoxin B1 immunosensor based on gold nanoparticle-decorated porous graphene nanoribbon and Ag nanocube-incorporated MoS2 nanosheets

Abstract: The accurate and precisive monitoring of aflatoxin B1 (AFB1), which is one of the most hazardous mycotoxins, especially in agricultural products, is significant for human and environmental health. AFB1 generally contaminates agricultural products such as corn and feedstuff. In this paper, a novel electrochemical AFB1 immunosensor was constructed based on Ag nanocubes (AgNCs) incorporated trigonal metallic MoS2 nanosheets with 1T phase (AgNCs/1T-MoS2) as signal amplification and gold nanoparticles/porous graphene nanoribbon (AuNPs/PGNR) as an electrochemical sensor platform. First, the chronoamperometry method was implemented to provide electrodeposition of AuNPs on PGNR following chemical reduction of PGNR. Immobilization of the primer AFB1 antibody was performed via amino-gold affinity between primer antibody and AuNPs/PGNR composite. Subsequently, the conjugation of seconder antibody to AgNCs/1T-MoS2 was performed by strong π–π and electrostatic interactions. To describe the surface morphology and elemental composition of the prepared electrochemical AFB1 immunosensor, physicochemical characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used. Furthermore, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques were used to evaluate the immunosensor's electrochemical performance. The developed electrochemical AFB1 immunosensor offered a good sensitivity with a detection limit (LOD) of 2.00 fg mL−1. Finally, an electrochemical AFB1 immunosensor with satisfactory selectivity, stability and reusability was applied in wheat samples with high recovery.

Nanoparticles Modified with Cell-Penetrating Peptides: Conjugation Mechanisms, Physicochemical Properties, and Application in Cancer Diagnosis and Therapy.

Abstract: Based on their tunable physicochemical properties and the possibility of producing cell-specific platforms through surface modification with functional biomolecules, nanoparticles (NPs) represent highly promising tools for biomedical applications. To improve their potential under physiological conditions and to enhance their cellular uptake, combinations with cell-penetrating peptides (CPPs) represent a valuable strategy. CPPs are often cationic peptide sequences that are able to translocate across biological membranes and to carry attached cargos inside cells and have thus been recognized as versatile tools for drug delivery. Nevertheless, the conjugation of CPP to NP surfaces is dependent on many properties from both individual components, and further insight into this complex interplay is needed to allow for the fabrication of highly stable but functional vectors. Since CPPs per se are nonselective and enter nearly all cells likewise, additional decoration of NPs with homing devices, such as tumor-homing peptides, enables the design of multifunctional platforms for the targeted delivery of chemotherapeutic drugs. In this review, we have updated the recent advances in the field of CPP-NPs, focusing on synthesis strategies, elucidating the influence of different physicochemical properties, as well as their application in cancer research.