Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

• synthetic pathways for the formation of CDs, that is, “top-down” and “bottom-up” methods. In the top-down method, large carbon structures (such as carbon nanotubes or graphite) are decomposed into CDs. The top-down methods include arc discharge, laser abrasion [24], chemical and electrochemical oxidation

• material is oxidized and broken down into CDs using oxidants such as sulfuric acid and nitric acid. As green methods are limited regarding the raw materials, the “top-down” method is not very common in green approaches [3][50]. The “bottom-up” method consist of carbonization of smaller organic molecules

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• effect; strain sensors; strain tests; top-down method; Introduction Due to the non-centrosymmetric structure of the group-III nitride semiconductor materials (e.g., GaN, AlN, and AlGaN), spontaneous polarization (Psp) and piezoelectric polarization induced by lattice mismatch (Plm) are inevitably

Self-assembled quasi-hexagonal arrays of gold nanoparticles with small gaps for surface-enhanced Raman spectroscopy

• Emre Gürdal,
• Simon Dickreuter,
• Fatima Noureddine,
• Pascal Bieschke,
• Dieter P. Kern and
• Monika Fleischer

Beilstein J. Nanotechnol. 2018, 9, 1977–1985, doi:10.3762/bjnano.9.188

• enhanced Raman spectroscopy (SERS) [10]. Ordered arrays of such particles can be fabricated by different methods. Electron-beam lithography for example is a top-down method which provides good control, but is time consuming and costly. In contrast, the self-assembly of block-copolymers is a bottom-up

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls

• Carlos Angulo Barrios and
• Víctor Canalejas-Tejero

Beilstein J. Nanotechnol. 2017, 8, 1231–1237, doi:10.3762/bjnano.8.124

• , Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain 10.3762/bjnano.8.124 Abstract We report on a top-down method for the controlled fabrication of three-dimensional (3D), closed, thin-shelled, hollow nanostructures (nanocages) on planar supports. The presented approach is based

Methods for rapid frequency-domain characterization of leakage currents in silicon nanowire-based field-effect transistors

• Tomi Roinila,
• Xiao Yu,
• Jarmo Verho,
• Tie Li,
• Pasi Kallio,
• Matti Vilkko,
• Anran Gao and
• Yuelin Wang

Beilstein J. Nanotechnol. 2014, 5, 964–972, doi:10.3762/bjnano.5.110

• from a SiNW FET. An n-type SiNW FET device was fabricated by using a silicon-on-insulator (SOI) wafer with a top-down method. A full description of the fabrication process is given in [25]. The structure of the device is schematically shown in Figure 4, where G, S, and D denote the gate, source, and

Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

• Alexander Weddemann,
• Inga Ennen,
• Anna Regtmeier,
• Camelia Albon,
• Annalena Wolff,
• Katrin Eckstädt,
• Nadine Mill,
• Michael K.-H. Peter,
• Jochen Mattay,
• Carolin Plattner,
• Norbert Sewald and
• Andreas Hütten

Beilstein J. Nanotechnol. 2010, 1, 75–93, doi:10.3762/bjnano.1.10

• we further analyze different properties of granular giant magnetoresistance sensors based on their spin-dependent transport properties. Review 1. Particle preparation In principle, two different strategies for the synthesis of nanoparticles may be pursued. The top-down method starts from the bulk