Table 1.

Overview of the currently available tools and techniques for detecting monoamine neuromodulators.

	DA	NE	5-HT	OA &TA
GC/HPLC/MEKC-electrochemistry/MS	Musshoff et al., 2000 [49] Carrera et al., 2007 [50]	Kuhlenbeck et al., 2000 [51] Carrera et al., 2007 [50]	Carrera et al., 2007 [50]	Watson et al., 1993 [38] Powell et al., 2005 [40] Hardie et al., 2006 [39]
Electrochemistry	Robinson et al., 2008 [15] Dreyer et al., 2016 [14]	Robinson et al., 2008 [15] Bucher et al., 2015 [26]	Marcinkiewcz et al., 2016 [32] Saylor et al., 2019 [33]	Cooper et al., 2009 [27] Fang et al., 2011 [43] Majdi et al., 2015 [42] Pyakurel et al., 2016 [41]
Microdialysis-biochemistry	Gu et al., 2015 [12] Nesbitt et al., 2015 [13]	McReynolds et al., 2010 [25]	Gardier et al., 2013 [31]	N.A.
FFNs	Gubernator et al., 2009 [17] Rodriguez et al., 2013 [19] Pereira et al., 2016 [52]	N.A.	Henke et al., 2018 [52]	N.A.
Tango assay	Barnea et al., 2008 [20] Inagaki et al., 2012 [21] Lee et al., 2017 [22] Kim et al., 2017 [23]	Hanson et al., 2009 [53] Kroeze et al., 2015 [54]	Hanson et al., 2009 [53] Kroeze et al., 2015 [54]	N.A.
CNiFER	Muller et al., 2014 [16]	Muller et al., 2014 [16]	Yamauchi et al., 2011 [55]	N.A.
FRET-based sensors	N.A.	Hoffmann et al., 2005 [29] Vilardaga et al., 2003 [30]	Candelario et al., 2012 [34]	N.A
GRAB/dLight	Sun et al., 2018 [10] Patriarchi et al., 2018 [9]	Feng et al., 2019 [8]	N.A.	N.A.
Nanosensor	Kruss et al., 2017 [56] Beyene et al., 2019 [11]	N.A.	N.A.	N.A.

DA, dopamine; NE, norepinephrine; 5-HT, 5-hydroxytryptamine (serotonin); OA, octopamine; TA, tyramine; N.A., not available; GC, gas chromatography; HPLC, high-performance liquid chromatography; MEKC, micellar electrokinetic capillary chromatography; MS, mass spectrometry; FFNs, fluorescent false neurotransmitters; CNiFER, cell-based neurotransmitter fluorescent engineered reporter; FRET, Förster resonance energy transfer; GRAB, GPCR activation-based sensor.