Primers

Photocatalytic water splitting produces clean H₂ gas by converting light to chemical energy. In this Primer, Nishioka et al. describe reliable methods for conducting experiments and the proper characterization and evaluation techniques to improve reproducibility in this field.

X-ray photoelectron spectroscopy (XPS) can be used to investigate chemical bonding and elemental composition. This Primer discusses how XPS can be used to characterize thin films, including key considerations for sample preparation, experimental set-up and data analysis.

Triboelectric nanogenerators (TENGs) convert mechanical energy into electric power by combining contact electrification and electrostatic induction. This Primer introduces the theoretical background of TENGs, gives an overview of fabrication methods and discusses how they can be applied as energy harvesting devices and self-powered systems.

Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) is a variation of surface-enhanced Raman spectroscopy (SERS) that uses shell-isolated nanoparticles (SHINs) to prevent direct contact between the core of the nanoparticle and the tested substances. In this Primer, Zhang et al. describe the design considerations for shell-isolated nanoparticles, relevant experimental instrument set-ups and ways to ensure experimental reproducibility and data analysis.

Participatory action research (PAR) involves the participation and leadership of people experiencing issues, who take action to produce emancipatory social change, through conducting systematic research to generate new knowledge. In this Primer, Cornish et al. set out key considerations for the design of a PAR project and discuss ways to overcome the challenges faced by PAR projects.

Droplet-based microfluidic systems generate microlitre droplets, giving users precise control over the chemical and biological contents of each droplet. In this Primer, Moragues et al. discuss the optimal use of droplet-based microfluidic systems and the most successful applications in biological and chemical sciences.

Contrast agents based on nanomaterials are highly desired for advanced forms of bioimaging techniques owing to their high payloads, unique physicochemical properties and improved sensitivity. In this Primer, Hsu et al. outline important nanomaterial design considerations and discuss the effect on their physicochemical attributes, contrast properties and biological behaviour.

Integrated catalysis can streamline multi-step syntheses in a single reaction vessel to achieve a high degree of control and reduce the waste and cost of chemical processes. In this Primer, Deng et al. discuss the underlying mechanisms of common approaches to integrated catalysis, highlighting recent advances in the field.

Peptidomics employs techniques of genomics, modern proteomics, state-of-the-art analytical chemistry and computational biology. In this Primer, Hellinger et al. describe the techniques and workflows required for peptide discovery and characterization and give an overview of biological and clinical applications of peptidomics.

Analytes can be ionized and brought into the gas phase using electrospray ionization (ESI). Coupling ESI with mass spectrometry enables a wide range of molecules to be studied, including proteins and polymers. This Primer introduces the ESI method, describing the underlying mechanism, common variants and instrument setups.

Mutations in mitochondrial DNA can cause several life-limiting diseases, raising interest in mitochondrial gene editing via nucleases and base editors. In this Primer, Shoop et al. discuss mitochondrial gene editing tools, analyses and limitations in the field.

Isothermal titration calorimetry uses the heat of a reaction to study molecular interactions in solution. This Primer introduces the method, from fundamental principles and experimental set-up, to applications involving complex biological interactions.

Extended reality allows users to be immersed in a virtual environment, with implications for biomedical research and applications. Yuan, Hassan et al. discuss the adoption of extended reality in biomedical research, with a focus on technical advances that overcome current limitations.

Plasmon-mediated chemical reactions use nanostructure-based surface plasmons as mediators to drive chemical reactions. Zhan et al. outline the primary considerations and techniques for designing and constructing plasmonic catalysts and describe the typical methods used to characterize plasmonic catalysts and their reaction mechanisms.

Behavioural genetics examines the underlying factors associated with individual differences in behaviours and capacities. In this Primer, Willoughby et al. discuss the methods used in behavioural genetics analysis, in particular twin studies, genome-wide association studies and statistical modelling.

Single-cell pathogen diagnostic tools are increasingly being used to identify and monitor bacterial infections and antimicrobial resistance. In this Primer, Li et al. discuss the assessment, design and implementation of single-cell pathogen diagnostics.

Molecular quantitative trait locus (molQTL) mapping associates genetic variation with molecular traits that can be measured as gene expression, splicing and chromatin accessibility. In this Primer, Aguet et al. discuss the study design and implementation of molQTL mapping in various applications, with a focus on technical developments for functional characterization.

Covalent organic frameworks (COFs) are a class of crystalline porous polymers consisting of highly ordered organic structures formed by polymerization. In this Primer, Tan et al. discuss the design principle, experimental methods, characterization and applications of COFs.

Principal component analysis is a multivariate statistical method that reduces a large number of variables into fewer variables, called principal components. This Primer describes how the method can be used for data analysis, explaining the mathematical background, analytical workflows, how to interpret a biplot and variants of the method.

Hydrogels are used to mimic cells’ local environment, enabling the study of cellular responses to biochemical and mechanical cues. Here, Blache et al. discuss the challenges of creating hydrogels for mechanobiology studies and how they can be used to analyse cell behaviour in the context of mechanobiological processes and harnessed to create regenerative therapies.