Interferometric nanoimmunosensor for label-free and real-time monitoring of Irgarol 1051 in seawater

• Published in: Biosensors & bioelectronics 2018-10, Vol.117, p.47-52
• Main Authors: Chocarro-Ruiz, Blanca, Herranz, Sonia, Fernández Gavela, Adrián, Sanchís, Josep, Farré, Marinella, Marco, M. Pilar, Lechuga, Laura M.
• Format: Article
• Language: English
• Subjects: Bimodal waveguide biosensor; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Competitive immunoassay; Environmental monitoring; Environmental Monitoring - instrumentation; Environmental Monitoring - methods; Interferometry; Irgarol 1051; Limit of Detection; Seawater - chemistry; Triazines - analysis; Water Pollutants, Chemical - analysis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2018.05.044

An interferometric nanobiosensor for the specific and label-free detection of the pollutant Irgarol 1051 directly in seawater has been settled. Due to the low molecular weight of Irgarol pollutant and its expected low concentration in seawater, the sensor is based on a competitive inhibition immunoassay. Parameters as surface biofunctionalization, concentration of the selective antibody and regeneration conditions have been carefully evaluated. The optimized immunosensor shows a limit of detection of only 3 ng/L, well below the 16 ng/L set by the EU as the maximum allowable concentration in seawater. It can properly operate during 30 assay-regeneration cycles using the same sensor biosurface and with a time-to-result of only 20 min for each cycle. Moreover, the interferometric nanosensor is able to directly detect low concentrations of Irgarol 1051 in seawater without requiring sample pre-treatments and without showing any background signal due to sea matrix effect. •Implementation of an effective nanobiosensor for the label-free and real-time monitoring of Irgarol 1051 in seawater.•The biosensor is able to directly detect Irgarol 1051 in undiluted seawater with no sample pre-treatment.•The limit of detection in real samples is 3 ng/L, well below the 16 ng/L set by the EU as the maximum allowable concentration.•The biosensor is able to carry out up to 30 measurement-regeneration cycles in 20 min each.