A Non-Enzymatic Electrochemical Sensor for Glyphosate Adopting Surface Modified Screen-Printed Electrodes

Abstract

In this study, a lab-on-chip electrochemical sensor was developed for ultratrace determination of glyphosate. A singlestep approach was adopted for the surface modification of screenprinted electrodes using reduced graphene oxide. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to characterize the electrochemical behavior of the modified electrode. The modified electrode exhibited lowered electron transfer resistance, improved current response, and demonstrated selectivity and sensitivity toward glyphosate. Differential pulse voltammetry was employed to quantify glyphosate. The detection limit for glyphosate was achieved up to 0.144 nmol L −1 for a wide concentration range of 1 to 1000 nM. The proposed sensor presents the advantage of nonenzymatically and specifically determining glyphosate and offers exceptional stability with a relative standard deviation of 3.3% for 10 days. Finally, the applicability of the developed technique was assessed by quantification of glyphosate in tap water and garden soil samples. The ease of fabrication and implementation of the proposed sensor can contribute to the quest for on-site determination of the ecological contaminants.

Disposable Saliva Sensors for Early Cancer Diagnosis Using Hyper-Cross-Linked Molecularly Imprinted Polymeric Electrocatalysts

“…The corresponding limit of detection (LOD) and limit of quantification (LOQ) are estimated using 3.3σ/S and 10σ/S, respectively. 31,32 The sPMA2TA@g-C 3 N 4 sensor reveals the lowest LOD (37.5 pM) and LOQ (113.7 pM), which validates extraordinary spermine sensitivity for noninvasive salivary cancer diagnosis. Cross-Sensitivity of the High-Performing Sensors.…”

“…Figure b shows the relative sensitivities of different spermine sensors, with a maximum of 0.82 μA cm –2 for the sPMA2TA@g-C 3 N 4 sensor. The corresponding limit of detection (LOD) and limit of quantification (LOQ) are estimated using 3.3σ/ S and 10σ/ S , respectively. , The sPMA2TA@g-C 3 N 4 sensor reveals the lowest LOD (37.5 pM) and LOQ (113.7 pM), which validates extraordinary spermine sensitivity for noninvasive salivary cancer diagnosis.…”

Plastic Chip Electrode: An Emerging Multipurpose Electrode Platform

“…The screen-printed electrode is highly exploited in commercial applications as well as in interdigitated array electrodes and lab-on-a-chip. [41] Although, the major bottleneck with coated and screen-printed electrodes, as discussed in section 4.3.2, is that the conducting layers are not an integral part of the base/ substrate on which the electrode is fabricated, and it can easily be delaminated by a mechanical jerk or high current. The Plastic Chip Electrode (PCE) provides an opportunity to overcome all the above bottlenecks.…”