Rapid monitoring and early warning of Phaeocystis globosa bloom based on an effective electrochemical biosensor

Harmful algal blooms (HABs) have posed a significant threat to human society and the ecological environment. In particular, the outbreak of Phaeocystis globosa ( P. globosa ) bloom could affect coasts nuclear power safety. Unfortunately, current ecological monitoring tools fail to dynamically detect the densities of solitary cells from P. globosa in the pre-outbreak phases, thus affecting early interventions. In the study, an effective electrochemical DNA biosensor was developed to serve the rapid and effective detection of P. globosa DNA through a specific DNA probe strategy. Especially, its good specificity and lower limit of detection (LOD, 17 pg/μL or 1063 cells/L) met the monitoring requirement of solitary-cell population change of P. globosa before the cyst formation (threshold: 1.0 × 10 7 cells/L), which is the key step in the algal bloom outbreaks and influences the outbreak cycle and scale. Furthermore, the accuracy of this electrochemical biosensor for the quantitative detection of solitary-cell P. globosa was confirmed by using the classical microscopic examination techniques (r = 0.981, P < 0.001). Moreover, its applicability was also validated by actual sample testing (r = 0.996, P < 0.001). Therefore, the novel technology offers great potential to improve dynamic detection and early warning of P. globosa bloom.