[Impact Case] Development of E-nose-based Fast Detection Technique for Brown Root Rot Disease Infected Trees

Recently Brown Root Rot Disease (BRRD) caused by fungal pathogen Phellinus noxius (also denoted as P. noxius) was spotted with increased frequency. This disease results in rapid health and structural deterioration of trees and may lead to tree failure, thus posting a serious threat to public safety. Prof. Lee Shun-cheng (Principal Investigator) with Dr. Leu Shao-yuan (Co-Principal Investigator) and Dr. Wong Man-sing (Project Adviser) are invited by The Highways Department of The Government of Hong Kong Special Administrative Region to provide a service of development and evaluation of E-nose-based fast detection technique for BRRD infected trees. This fast and non-destructive diagnosis to detect the BRRD infected tree enables early action to be carried out to minimize the spread of BRRD and the risk on public safety.

Currently, a two-step diagnosis (including field and laboratory diagnosis) is adopted in Hong Kong. Observation-based diagnosis may not accurate enough, and may cause open wounds to the trees, which may lead to other infections, while laboratory diagnosis, on the other hand, requires days to obtain results.

Using E-nose is a non-destructive alternative, and possible to identify the suspected BRRD infection in just a few minutes. E-nose system is composed of an array of gas sensors, with the capability of responding to a group of gaseous chemicals for each sensor. When a mixture of complex gaseous chemicals is introduced to the E-nose system, the system will respond with a pattern showing the compositional characteristic of this mixture. When the volatile organic compounds (VOCs) emission marker(s) of BRRD emission is determined, it is possible to program the E-nose system to respond to some specific patterns indicating suspect of BRRD infection.