Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

• Akif Hakan Kurt,
• Elif Berna Olutas,
• Fatma Avcioglu,
• Hamza Karakuş,
• Mehmet Ali Sungur,
• Cansu Kara Oztabag and
• Muhammet Yıldırım

Beilstein J. Nanotechnol. 2023, 14, 362–376, doi:10.3762/bjnano.14.31

• continued attention due to the unique properties of quercetin. Caffeic acid (3,4-dihydroxycinnamic acid) is a natural phenolic acid with high antioxidant capacity due to the catechol group. It is present in, for example, fruits, olive oil, green tea, coffee, vegetables, and white wine [29][30]. In addition

LED-light-activated photocatalytic performance of metal-free carbon-modified hexagonal boron nitride towards degradation of methylene blue and phenol

• Nirmalendu S. Mishra and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2022, 13, 1380–1392, doi:10.3762/bjnano.13.114

• identified as catechol (m/z: 111), 4-hydroxybenzaldehyde (m/z: 122), salicylic acid (m/z: ≈138), benzene-1,2,3-triol (m/z: ≈126), maleic acid (m/z: ≈118), (Z)-4-oxobut-2-enoic acid (m/z: ≈98), (Z)-hex-3-enedioic acid (m/z: ≈146), and oxalic acid (m/z: ≈91) [47][48]. Conclusion The comprehensive analysis of

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• effectively [94]. To this end, iron oxide nanoparticles were coated with catechol-conjugated poly(vinylpyrrolidone) sulfobetaine and then self-assembled with poly(3,4-ethylenedioxythiophene). The latter polymer is capable of absorbing NIR light while capturing the bacteria, effectively releasing heat under

• membrane stress, which is enhanced by the photothermal effect upon sunlight irradiation [102]. Antibacterial continuous flow poly(dimethylsiloxane)-based microreactors with microchannels were fabricated using catechol-grafted poly(N-vinylpyrrolidone) and NIR-active Cs0.33WO3 nanoparticles [103]. Upon NIR

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

• Boris N. Khlebtsov,
• Andrey M. Burov,
• Timofey E. Pylaev and
• Nikolai G. Khlebtsov

Beilstein J. Nanotechnol. 2019, 10, 794–803, doi:10.3762/bjnano.10.79

• ], Fe3O4 [35], graphene [36], and many others [37][38]. The PDA shell surface contains numerous catechol and quinone groups suitable for click conjugation with various biomolecules through Michael addition and Schiff-base reaction [39][40]. The high loading capacity and biocompatibility of the PDA layer

Uniform cobalt nanoparticles embedded in hexagonal mesoporous nanoplates as a magnetically separable, recyclable adsorbent

• Can Zhao,
• Yuexiao Song,
• Tianyu Xiang,
• Wenxiu Qu,
• Shuo Lou,
• Xiaohong Yin and
• Feng Xin

Beilstein J. Nanotechnol. 2018, 9, 1770–1781, doi:10.3762/bjnano.9.168

• . Thus, LDHs possess great potential, serving as ideal precursors for the preparation of 2D TM-MCNs. To achieve the reduction of metal cations by carbon in LDH lattices, a suitable carbon precursor is required. Dopamine (DA), a small biomolecule containing both amino and catechol functional groups, can

A biofunctionalizable ink platform composed of catechol-modified chitosan and reduced graphene oxide/platinum nanocomposite

• Peter Sobolewski,
• Agata Goszczyńska,
• Małgorzata Aleksandrzak,
• Karolina Urbaś,
• Joanna Derkowska,
• Agnieszka Bartoszewska,
• Jacek Podolski,
• Ewa Mijowska and
• Mirosława El Fray

Beilstein J. Nanotechnol. 2017, 8, 1508–1514, doi:10.3762/bjnano.8.151

• , Szczecin, Poland 10.3762/bjnano.8.151 Abstract We present an ink platform for a printable polymer–graphene nanocomposite that is intended for the development of modular biosensors. The ink consists of catechol-modified chitosan and reduced graphene oxide decorated with platinum nanoparticles (rGO–Pt). We

• modified the chitosan with catechol groups, in order to obtain adhesive properties and improve solubility. Dispersions of rGO–Pt in ethylene glycol were admixed with an aqueous solution of modified chitosan to yield an ink that is suitable for non-contact piezoelectric printing using a commercial

• polymerase chain reaction (PCR) products and low non-specific binding. Our results demonstrate that catechol-modified chitosan/rGO–Pt nanocomposites can be used as inks for piezoelectric printing and facilitate the attachment of biorecognition elements for biosensor applications. Keywords: biosensing

Photocatalysis applications of some hybrid polymeric composites incorporating TiO₂ nanoparticles and their combinations with SiO₂/Fe₂O₃

• Andreea Laura Chibac,
• Tinca Buruiana,
• Violeta Melinte and
• Emil C. Buruiana

Beilstein J. Nanotechnol. 2017, 8, 272–286, doi:10.3762/bjnano.8.30

• eliminated after 250 min of irradiation. We also tested the performance of our catalysts in the decomposition of dopamine, which has a catechol structure (a benzene ring with two hydroxyl side groups) and an amine group attached via an ethyl chain. From the best of our knowledge, the dopamine

Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

• Celia García-Hernández,
• Cristina García-Cabezón,
• Fernando Martín-Pedrosa,
• José Antonio De Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2016, 7, 1948–1959, doi:10.3762/bjnano.7.186

• electrodes chemically modified with PEDOT/PSS towards catechol and hydroquinone sensing have been successfully improved by combining layers of PEDOT/PSS with layers of a secondary electrocatalytic material such as gold nanoparticles (PEDOT/PSS/AuNPs), copper phthalocyanine (PEDOT/PSS/CuPc) or lutetium

• excellent electrocatalytic activity towards the oxidation of catechol. The kinetic studies demonstrated diffusion-controlled processes at the electrode surfaces. The kinetic parameters such as Tafel slopes and charge transfer coefficient (α) confirm the improved electrocatalytic activity of the layered

• electron mediators. The peak currents increased linearly with concentration of catechol and hydroquinone over the range of 1.5 × 10−4 to 4.0 × 10−6 mol·L−1 with a limit of detection on the scale of μmol·L−1. The layered composite hybrid systems were also found to be excellent electron mediators in

Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol

• Celia García-Hernández,
• Cristina García-Cabezón,
• Cristina Medina-Plaza,
• Fernando Martín-Pedrosa,
• Yolanda Blanco,
• José Antonio de Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209

• electrochemical sensor, the Ppy/AuNp deposited on platinum exhibited a strong electrocatalytic activity towards the oxidation of catechol. The effect was higher in films obtained by CP than in films obtained by chronoamperometry (CA). The influence of the method used to introduce the AuNPs (trapping or

• effects are not so pronounced on stainless steel, but acceptable LOD are attained with lower price sensors. Keywords: catechol; conducting polymers; electropolymerization; gold nanoparticles (AuNPs); polypyrrole; Introduction Polypyrrole (Ppy) is one of the most extensively studied, conducting polymers

• based on electrodeposited Ppy/AuNps for the detection of catechol (an antioxidant of interest in the food industry) and to evaluate the influence of the electrodeposition method in their performance. For this purpose Ppy/AuNp films doped with 1-decanesulfonic acid (DSA) were deposited using different

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• ) confluent films as a substrate-independent modification approach. The ability of PDA to adhere to solid surfaces stems from the reactivity of ortho-quinone/catechol moieties that form coordination bonds with surface metal oxides and covalent bonds with nucleophilic groups. In addition to this, the different

• the hydrolysis reaction. The spectrum of a solid dopamine monomer (Figure 2C) is characterized by skeletal vibration modes of aromatic double bonds (1650–1400 cm−1), stretching ν(C–O) modes of the catechol moieties at 1283 cm−1, in-plane bending δin-plane(C–H) at 1170 cm−1 and stretching modes ν(C–C–N

• free hydroxy groups. (B) Immobilization of neridronate, APTES siloxane and poly(dopamine) anchor layers through surface specific reactions between the phosphonate, silane and catechol groups of corresponding compounds and hydroxy groups on the surface. (C) Covalent binding of ALG chains to amino groups

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• exchange and covalent grafting of catechol ligands. Up to now, large technical applications of Janus particles are restricted by the lack of accessibility. Therefore, polymer-modified kaolinite provides the enormous advantage as an abundant, ubiquitous, and inexpensive mineral, which can be used as

Controlling mechanical properties of bio-inspired hydrogels by modulating nano-scale, inter-polymeric junctions

• Seonki Hong,
• Hyukjin Lee and
• Haeshin Lee

Beilstein J. Nanotechnol. 2014, 5, 887–894, doi:10.3762/bjnano.5.101

• derivatives, PEG-NH-catechols that can utilize an expanded spectrum of catecholamine chemistry. The PEGs enable simultaneous participation of amine and catechol in quinone tanning crosslinking. The intermolecular reaction between PEG-NH-catechols forms a dramatic nano-scale junction resulting in enhancement

• strategies for the functionalization of virtually any material surfaces by using synthetic catecholamine polymers such as poly(dopamine) [12], poly(norepinephrine) [13], and poly(ethylenimine)-catechol [14]. The surfaces modified by those catecholamines exhibited a variety of functionalities such as protein

• ) (PEG) and pluronic hydrogels have been reported [22][23][24][25][26]. However, most previous work utilized catechol–catechol crosslinking by using catechol end-functionalized polymers, which limits the control of important variables in hydrogels such as gelation kinetics and mechanical properties

A catechol biosensor based on electrospun carbon nanofibers

• Dawei Li,
• Zengyuan Pang,
• Xiaodong Chen,
• Lei Luo,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2014, 5, 346–354, doi:10.3762/bjnano.5.39

• morphologies of the CNFs and of the mixtures. Cyclic voltammetry and chronoamperometry were employed to study the electrocatalysis of the catechol biosensor. The results indicated that the sensitivity of the biosensor was 41 µA·mM−1, the detection limit was 0.63 µM, the linear range was 1–1310 µM and the

• response time was within 2 seconds, which excelled most other laccase-based biosensor reported. Furthermore, the biosensor showed good repeatability, reproducibility, stability and tolerance to interferences. This novel biosensor also demonstrated its promising application in detecting catechol in real

• water samples. Keywords: biosensor; carbon nanofibers; catechol; electrospinning; laccase; Introduction Nowadays, carbon nanomaterials attract a great deal of attention due to their high surface area, excellent electronic conduction and biocompatibility. Among these, mesoporous carbon [1][2][3][4][5

Synthesis and catalytic applications of combined zeolitic/mesoporous materials

• Jarian Vernimmen,
• Vera Meynen and
• Pegie Cool

Beilstein J. Nanotechnol. 2011, 2, 785–801, doi:10.3762/bjnano.2.87

• importance of TS-1 for oxidation catalysis (the three upper reactions in Figure 10) [171][172][182][183]: Hydroxylation of phenol: This reaction occurs in aqueous or aqueous-organic medium producing a mixture of hydroquinone (p-dihydroxybenzene) and catechol (o-dihydroxybenzene), which can be used as a