Background:
Sarcosine, also known as N-methyl glycine, is a natural amino acid that is an
intermediate and by product in glycine synthesis and degradation. Recently found in many
peptides, sarcosine has been researched as a newly accepted prostate cancer marker. The
increased concentration of sarcosine in blood serum and the urine showed that malignancy of
measured prostate cancer cells is active.
Objective:
In this article, we aimed to design a potentiometric biosensor for
detection of sarcosine with a low detection limit, high selectivity, short response time, wide
linear range, and satisfactory long-term stability.
Methods:
In this article, we developed a new Graphene oxide (GFOX) photosensitive cross-
linker based potentiometric biosensor based on the AmiNoAcid (monomer) Decorated and
Light Underpinning Conjugation Approach (ANADOLUCA) method. The functional groups
determined using Raman, FT-IR, XPS analyzes, and surface characterization, the morphology of
synthesized GFOX photosensitive cross-linker were determined by TEM and AFM studies.
Then, the performance of the GFOX based potentiometric biosensor has been evaluated.
Results:
When the usage of the developed GFOX doped potentiometric biosensor against
sarcosine determination, it was found that 10 -4 mM sarcosine was determined in 60 seconds in the solution. In addition, the detection limit of the GFOX doped potentiometric biosensor was
found to be 9.45x10 -7 mM, and the linear potentiometric biosensor was found to be in the
concentration range of 10 -1 to 10 -5 mM. The selectivity studies of the developed potentiometric
biosensor were investigated using glycine solutions, and it was determined that GFOX doped
potentiometric biosensor was more selective against sarcosine. Besides this, a reusability test
using 10 -3 mM sarcosine solution showed that reproducible studies were performed without
the loss of potential of designed potentiometric biosensor and no loss of sensitivity.
Conclusion:
After applying the framework, we get a new potentiometric biosensor for
sarcosine determination. GFOX photosensitive cross-linker was used in designing
potentiometric biosensors, and this increased the stability and efficiency of the biosensor.
Therefore, the developed potentiometric biosensor for sarcosine determination could be easily used
for the early diagnosis of prostate cancer.