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

Abstract

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 × 10⁷ 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.