Sensors 2014, 14, 17275-17303; doi:10.3390/s140917275 OPEN ACCESS sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Review Raman Spectroscopy for In-Line Water Quality Monitoring — Instrumentation and Potential Zhiyun Li 1, M. Jamal Deen 1,2,4,*, Shiva Kumar 2 and P. Ravi Selvaganapathy 1,3 1 School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada; E-Mails:
[email protected] (Z.L.);
[email protected] (P.R.S.) 2 Electrical and Computer Engineering, McMaster University, Hamilton, ON L8S 4K1 Canada; E-Mail:
[email protected] 3 Mechanical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada 4 Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China * Author to whom correspondence should be addressed; E-Mail:
[email protected] or
[email protected]; Tel.: +1-905-525-9140 (ext. 27137); Fax: +1-905-521-2922. Received: 1 July 2014; in revised form: 7 September 2014 / Accepted: 9 September 2014 / Published: 16 September 2014 Abstract: Worldwide, the access to safe drinking water is a huge problem. In fact, the number of persons without safe drinking water is increasing, even though it is an essential ingredient for human health and development. The enormity of the problem also makes it a critical environmental and public health issue. Therefore, there is a critical need for easy-to-use, compact and sensitive techniques for water quality monitoring. Raman spectroscopy has been a very powerful technique to characterize chemical composition and has been applied to many areas, including chemistry, food, material science or pharmaceuticals.