distribution of the diatom’s refractive index (RI). The RI image is more consistent than the image intensity of light transmitted through the specimen. These results, obtained from such advanced optical microscopy techniques, will be valuable in diatom nanotechnology, such as the fabrication of optimal diatom biofilms.
Despite the several applications of optical microscopy, a higher spatial resolution is necessary to uncover the deeper structural details of diatoms. Gopal et al. [1.4], have given recent insights into the ultrastructure of diatoms using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The topography of diatom frustules is studied using atomic force microscopy (AFM). Chakraborty et al. [1.2], have explored biomineral formation in diatoms using AFM. In addition, the authors have revealed the applications of AFM in studying the characteristics and function of the mucilage layer, micromechanical properties of the diatom frustule, and taxonomical classification of diatoms. The AFM study of diatoms can inspire designs and manufacturing of nanostructured materials with significant applications. In addition to AFM, X-ray based techniques are also used to analyse the properties of marine frustules, as they provide better results and information on diatom features as well as properties of the diatoms. Sunder et al. [1.9], summarised various X-ray based techniques to assess morphological, chemical, and functional properties of diatoms of various species. However, several factors exist that affect the physicochemical properties of diatoms. Biswas & Biswas [1.1], briefly describe the application of the surface enhanced Raman scattering (SERS) technique for various biophysical, physiological and optoelectronic properties of diatoms. Where diatoms are one of the preferred substrates for accomplishing analysis of common molecular species and the advent of fabrication protocols has enabled comprehensive analysis of diatom assisted SERS. Sen et al. [1.7], have discussed light as an essential factor that alters the properties of diatoms including their morphology, cellular structure, the composition of cell membrane lipids, and metabolism. The detailed characterization of diatoms helps in uncovering their applications in various fields. Tisso et al. [1.10], have discussed the potential application of luminescent diatom frustules in the optoelectronic, sensing, and biomedical fields. De et al. [1.3], have further elaborated on the application of diatoms as bio-derived transducers for label-free sensing, and based on their mechanisms they can be divided into various types such as optical, plasmonic, electrochemical, immunosensors, etc. Diatom-based sensors can be used in agriculture, industry, and medicine especially in the detection of biomarkers and point-of-care biosensing. Diatom frustules are an excellent cost-effective source of bio-silica, which can replace synthetic nanoporous silica materials. Viji S et al. [1.12], have highlighted the various optical properties of diatom frustules, thin film deposition, and eventual implementations in biological and chemical sensors with wide applications including biomedicine, sensing, photonics, energy storage, and conversion techniques. In summary, each chapter in this book gives detailed insight into the microscopic world of diatoms that deals with all aspects, from morphology, topography, ultrastructure, to detailed applications using several advanced microscopic techniques. We hope that researchers who occasionally use diatoms in their work, including archaeologists, forensic scientists, climatologists, etc., will also find the book useful.
We appreciate the authors for their contributions towards our book. We thank the authors for patience and timely submission and responses to the reviewers’ comments. We are grateful to the reviewers who spent their valuable time providing fruitful suggestions/comments for the chapters. We wish to acknowledge all of our colleagues who assisted us with their advice for this volume. Special appreciation to Martin Scrivener and Linda Mohr (Scrivener Publishing) for their cooperation on this book. Most importantly, we would like to thank all the contributors and wish our readers enjoyable and profitable browsing.
References
[1.1] Biswas, R. and Biswas, S. (2022) Chapter 9: Diatom assisted SERS. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 237-250.
[1.2] Chakraborty, I., Chakrabarti, S., Managuli, V. and Mazumder, N. (2022) Chapter 4: Atomic force microscopy study of diatoms. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 81-110.
[1.3] De, P. and Mazumder, N. (2022) Chapter 10: Diatoms as sensors and their applications. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 251-282.
[1.4] Gopal, D., Chakrabarti, S., Venkata, D., Keshav, S., Gordon, R. and Mazumder, N. (2022) Chapter 3: Recent insights into the ultrastructure of diatoms using scanning and transmission electron-microscopy. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 57-80.
[1.5] Khan, M.J., Mathy, D. and Vinayak, V. (2022) Chapter 7: Micro to nano ornateness of diatoms from geographically distant origins of the globe. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 179-220.
[1.6] Lin, S.-T., Lee, M.-X. and Zhuo, G.-Y. (2022) Chapter 1: Investigation of diatoms with optical microscopy. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 1-32.
[1.7] Sen, J., Dhawan, P., De, P. and Mazumder, N. (2022) Chapter 12: Effects of light on physico-chemical properties of diatoms. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 307-334.
[1.8] Soto, J.M., Rodrigo, J.A. and Alieva, T. (2022) Chapter 5: Refractive index tomography for diatom analysis. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 111-138.
[1.9] Sunder, M., Acharya, N., Nayak, S., Gordon, R. and Mazumder, N. (2022) Chapter 8: Types of x-ray techniques for diatom research. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 221-236.
[1.10] Tisso, J., Shetty, S., Mazumder, N., Gogoi, A. and Ahmed, G.A. (2022) Chapter 6: Luminescent diatom frustules: A review on the key research applications. In: Diatom Microscopy [DIMI, Volume in the series: Diatoms: Biology & Applications, series editors: Richard Gordon & Joseph Seckbach]. N. Mazumder and R. Gordon, (eds.) Wiley-Scrivener, Beverly, MA, USA: 139-178.
[1.11] Umemura, K. (2022) Chapter
