A Brief Review of Carbon Dots–Silica Nanoparticles Synthesis and their Potential Use as Biosensing and Theragnostic Applications

Table 2 Biomedical applications

Starting precursor	Synthesis method	Use	Application	References
Sargassum fluitans	Hydrothermal	DNA detection	Biosensors	[72]
Urea/citric acid	Solvothermal	RNA detection		[73]
o-Phenylenediamine, 2-aminoterephthalic acid	Solvothermal	microRNA-21 detection		[56]
Citric acid, basic fuchsin	Hydrothermal	Intracellular pH sensing		[74]
Citric acid, ethylenediamine	Hydrothermal	Spectrofluorometric detection of cancer cells		[75]
Diammonium hydrogen citrate	Pyrolysis	Escherichia coli and iron(III) detection		[36]
Poly(ethylene glycol) (PEG800), cyanine dye	Solvothermal	Near-infrared fluorescence imaging and photothermal cancer therapy	In vivo and in vitro imaging	[76]
Citric acid, polyethyleneimine (PEI)	Hydrothermal	Lysosome labeling and imaging		[77]
Polyethyleneimine (PEI)	Hydrothermal	Gene/drug delivery/imaging		[78]
Citric acid, thiourea, 3-aminophenylboronic acid	Hydrothermal	Glucosamine and liver cancer cell imaging		[79]
Carrot	Hydrothermal	Ratiometric two-photon fluorescence turn-on sensing of sulfide anion in biological fluids		[37]
Polyethyleneimine (PEI), folic acid (FA)	Hydrothermal	Gene therapy	Drug and gene delivery	[55]