The use of amitraz to control the Varroa destructor parasite in honeybee colonies is a common practice, widely employed by both amateur and professional beekeepers. Although effective against the parasite, the use of amitraz remains controversial because its toxic metabolite, 2,4-dimethylaniline (2,4-DMA), can persist in honey and beeswax, potentially causing serious environmental and health issues. Conventional chromatographic techniques are still used to detect these residues, but they are expensive, cumbersome, and not suitable for in-field applications. In this work, a fully lab-made 3D-printed electrochemical device for analyzing Amitraz is proposed. The device consists of a PLA functional scaffold featuring a hydrolysis rotary valve, designed to hold an interchangeable paper sensor. In brief, the 3D device's rotary valve allows for sample loading, and a disposable paper strip facilitates amitraz hydrolysis at 2,4-DMA. After opening the valve, the sample is transported to the sensor chamber, designed to hold the paper-based sensor, using a neutralization medium. The paper sensor provides the required electroanalytical performance to detect the analyte. Initially, several standard and recycled papers were tested in combination with different types of carbon-based conductive inks to create an effective paper sensor. The combination of drawing paper and carbon paste ink (DP-CP) proved to be optimal, offering a high electroactive surface area, low charge transfer resistance, and superior sensing ability toward 2,4-DMA. The 3D-printed device equipped with the DP-CP paper-sensor demonstrated excellent analytical performance, showing a wide linear range (0.05–100 μM), a low limit of detection (LOD = 14 nM), and good reproducibility (RSD ≤ 7%). Eventually, the applicability of the integrated platform has been confirmed on real matrices, including various types of honey and beeswax, yielding quantitative recoveries (95.8%–112.2%) and good reproducibility (RSD ≤ 12%). Summing up, a portable platform that includes all Amitraz analysis steps and provides reliable results in 10 min has been developed, combining the multifunctionality of paper with the versatility of 3D printing, enabling pretreatment-free analysis of beekeeping matrices.
Integrated 3D-printed/paper electrochemical device for the direct quantitative sensing of Amitraz
D. Paolini
;F. Della Pelle;C. Fantilli;C. Merola;A. Scroccarello;S. Fiori;D. Compagnone
2025-01-01
Abstract
The use of amitraz to control the Varroa destructor parasite in honeybee colonies is a common practice, widely employed by both amateur and professional beekeepers. Although effective against the parasite, the use of amitraz remains controversial because its toxic metabolite, 2,4-dimethylaniline (2,4-DMA), can persist in honey and beeswax, potentially causing serious environmental and health issues. Conventional chromatographic techniques are still used to detect these residues, but they are expensive, cumbersome, and not suitable for in-field applications. In this work, a fully lab-made 3D-printed electrochemical device for analyzing Amitraz is proposed. The device consists of a PLA functional scaffold featuring a hydrolysis rotary valve, designed to hold an interchangeable paper sensor. In brief, the 3D device's rotary valve allows for sample loading, and a disposable paper strip facilitates amitraz hydrolysis at 2,4-DMA. After opening the valve, the sample is transported to the sensor chamber, designed to hold the paper-based sensor, using a neutralization medium. The paper sensor provides the required electroanalytical performance to detect the analyte. Initially, several standard and recycled papers were tested in combination with different types of carbon-based conductive inks to create an effective paper sensor. The combination of drawing paper and carbon paste ink (DP-CP) proved to be optimal, offering a high electroactive surface area, low charge transfer resistance, and superior sensing ability toward 2,4-DMA. The 3D-printed device equipped with the DP-CP paper-sensor demonstrated excellent analytical performance, showing a wide linear range (0.05–100 μM), a low limit of detection (LOD = 14 nM), and good reproducibility (RSD ≤ 7%). Eventually, the applicability of the integrated platform has been confirmed on real matrices, including various types of honey and beeswax, yielding quantitative recoveries (95.8%–112.2%) and good reproducibility (RSD ≤ 12%). Summing up, a portable platform that includes all Amitraz analysis steps and provides reliable results in 10 min has been developed, combining the multifunctionality of paper with the versatility of 3D printing, enabling pretreatment-free analysis of beekeeping matrices.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
