Amperometric indicator displacement assay for biomarker monitoring: Indirectly sensing strategy for electrochemically inactive sarcosine

Abstract

Indicator displacement assay plays a fundamental role in the development of chemosensors. We explored here an ingenious yet effective strategy for amperometric assay of electrochemically inactive sarcosine based on an indicator displacement principle, in which 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS) was proposed as the receptor and the electroactive Ru(NH) cations used as an indicator. Due to the stronger binding affinity of the NQS toward sarcosine than toward Ru(NH), the developed amperometric indicator displacement assay (A-IDA) exhibits high selectivity and excellent sensitivity toward sarcosine determination as well as with a lower detection limit (30.00nM, S/N =3).

Development of sarcosine quantification in urine based on enzyme-coupled colorimetric method for prostate cancer diagnosis

“…However, the sensitivity of our method is sufficient because it encompasses the concentrations of sarcosine in urine samples (1-20 µM) (Valenti et al, 2015[ 33 ]). Notably, the reaction time of our assay is approximately 20 min which is shorter than that of other methods (Cernei et al, 2012[ 10 ]; Lan et al, 2014[ 21 ]; Xue et al, 2017[ 35 ]). Moreover, the amount of enzyme used in the reaction is much less than the amount from previous reports (Perez Galende et al, 2012[ 25 ]).…”

“…Nevertheless, it is higher than the LOD of the chromatography and electrochemical-based methods. In the literature, the LOD of sarcosine has been reported at nanomolar levels; 1 and 4 nM using GC-MS and LC-MS, respectively (Jiang et al, 2010[ 17 ]; Cavaliere et al, 2011[ 9 ]), 20 nM by fluorometric method (Burton et al, 2012[ 6 ]), 45 nM by reflectometric nanosensor (Diltemiz and Uslu, 2015[ 13 ]), 30 nM using amperometric biosensor (Xue et al, 2017[ 35 ]) and 16 nM using carbon screen-print electrode electrochemical biosensor (Rebelo et al, 2014[ 26 ]). However, the sensitivity of our method is sufficient because it encompasses the concentrations of sarcosine in urine samples (1-20 µM) (Valenti et al, 2015[ 33 ]).…”

Exploring the Significance of Carbon Quantum Dots and Graphene Quantum Dots in Sarcosine Sensing: A Key Biomarker for Prognosticating Prostate Cancer

“…Schematic presentation of sensing of sarcosine using A-IDA. Reproduced from ref, [86] Copyright (2017) with permission from Elsevier.…”

“…While all other interferences have very tiny signal changes sarcosine causes a clear shift in the electrochemical signal. [86] The sensing mechanism was depicted in Figure 6.…”

A Ti3C2TX/Pt–Pd based amperometric biosensor for sensitive cancer biomarker detection

“…To improve the sensitivity of sarcosine detection, various nanomaterials, such as graphene [27,28], carbon nanotube [29,30], and metal nanoparticles (NPs) [31,32], have been applied for electrode modification to facilitate electron transfer reaction. Still and all, these sensors cannot yet achieve highly sensitive detection of sarcosine in a wide concentration range.…”