A rare disease due to amino acid disorders is maple syrup urine smelling disease (MSUD). It is provoked by tremendous amounts of the L-branched-chain amino acid (b AAs), such as leucine, isoleucine, and valine (Leu, Ile, and Val, biomarkers) [2]. In malady, these excessive elevations of b AAs provoke complications such as liver illness, neurological impairments, and indeed death [2]. To avert these, it is exceptionally beneficial to receive a timely and rapid diagnosis in the prime periods of life due to the inevitable consequence on nurslings [2,3]. As can be seen by the lack of literature [4, 5, 6], electrochemical sensors have been rarely used in the detection of b AAs related to MSUD clinical diagnostics. The present study describes the green synthesis of silver nanoparticles (AgNPs) obtained using saffron [7]. The proposed AgNPs coupled saffron were electropolymerized using cyclic voltammetry (CV) on a carbon paste electrode. The electrochemical behaviour of the modified electrode was performed by CV. The morphology of the electrochemical sensor was characterized by electron scanning microscopy (SEM). The constructed electrochemical sensor was used in the detection of selected biomarkers of MSUD, determining its analytical features such as linearity, selectivity, sensitivity, and stability. This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme \"Human Resources Development, Education and Lifelong Learning\" in the context of the project \"Reinforcement of Postdoctoral Researchers--2 nd Cycle\" (MIS-5033021), implemented by the State Scholarships Foundation (IKY). ## References  
* Song et al. (2018) Song, Y.; Xu, C.; Kuroki, H.; Liao, Y.; Tsunoda, M. Recent trends in analytical methods for the determination of amino acids in biological samples. _J. Pharm. Biomed. Anal._**2018**, _147_, 35-49. * Harms and Olgemoller (2011) Harms, E.; Olgemoller, B. Neonatal screening for metabolic and endocrine disorders. _Dtsch. Arztebl. Int._**2011**, _108_, 11-22. * Burrage et al. (2014) Burrage, L.C. ; Nagamani, S.C.; Campeau, P.M.; Lee, B.H. Branched-chain amino acid metabolism: From rare Mendelian diseases to more common disorders. _Hum. Mol. Genet._**2014**, _23_, R1-R8. * Karastogianni and Girousi (2020) Karastogianni, S.; Girousi, S. Electrochemical (Bio)Sensing of Maple Syrup Urine Disease Biomarkers Pointing to Early Diagnosis: A Review. _Appl. Sci._**2020**, _10_, 7023. * Garcia-Carmona et al. (2018) Garcia-Carmona, L.; Gonzalez, M.C. ; Escarpa, A. Electrochemical On-site Amino Acids Detection of Maple Syrup Urine Disease Using Vertically Aligned Nickel Nanowires. _Electraanalysis_**2018**, _30_, 1505-1510. * Garcia-Carmona et al. (2019) Garcia-Carmona, L.; Gonzalez, M.C. ; Escarpa, A. On-line coupling of millimeter size motors and chronoamperometry for real time bio-sensing of branched-chain amino acids in maple syrup urine disease clinical samples. _Sens. Acturos B Chem._**2019**, _281_, 239-244. * Karastogianni and Girousi (2017) Karastogianni, S.; Girousi, S. A novel electrochemical bioimprinted sensor of butyl paraben on a modified carbon paste electrode with safranine-o capped to silver nanoparticles. _Int. J. Current Res._**2017**, \(9\), 61118-61124. * _Fluorescent Carbon Nanodots from Dualiella Salina Biomass and Their Application as a 4-Nitrophenol Nanoprobe_
* _Skolariki et al. (2017)_**T. Skolariki, T. G. Chatzimitakos and C. D. Stalikas
* Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece
* Correspondence: cstalika@uoi.gr
* _Dunaliella salina_, an algal biomass often found in natural lakes or marine waters, is known for producing carotenoids and glycerin [1]. In the present work, a solvothermal chemistry approach was applied for the synthesis of two different kinds of fluorescent carbon nanodots (CNDs), utilizing a natural precursor, i.e., biomass of halophilic microalgae _Dunaliella salina_. The strain of _Dunaliella salina_ used was isolated from the Greek salt works.