## 6 Conclusions  
The ability to manipulate particle structures at nanoscale has led to the emergence of a new class of engineered hybrid NPs, core-shell NPs. The developments in the field of greener synthesis of NPs in general and for core-shell NPs in particular has prompted us to summarize the current status in this field. The focus has been on introducing core-shell NPs, their synthesis with emphasis on greener methods, and their applications in a variety of scientific disciplines. Successful further scientific research and the industrial implementation of applications in this area may help to improve the quality \begin{table}
\begin{tabular}{c l l l l} \hline \hline
**No.** & **Nanoparticles Type** & **Application** & **Details** & **Ref.** \\ \hline \multirow{3}{*}{1} & \multirow{3}{*}{CoFe\({}_{2}\)O\({}_{4}\)@SiO\({}_{2}\)-NH\({}_{2}\)} & \multirow{3}{*}{Remove heavy metals} & The regenerable magnetic nanospheres could be potential adsorbents for the effective and removal of heavy metal ions (Cd(II), Cu(II) and Pb(II) from aqueous solutions. & [91] \\  & & & & \\ \hline \multirow{3}{*}{2} & \multirow{3}{*}{Au-Ag, Ag-Au} & Chemical and biomolecular Sensor & Surface-enhanced Raman scattering & [90] \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{3} & \multirow{3}{*}{Au-Ag} & \multirow{3}{*}{Detection drugs} & Chemiluminescence detection of anticancer drug, Raloxifene hydrochloride & [60] \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{5} & \multirow{3}{*}{Fe core and a thin ferrite} & Biosensor development of new diagnostic platforms & Multiplexed intracellular sensing of forum RNAs in MCF-7 human breast cancer cells using AuNPs with a dense shell of multicolored molecular beacons. These show high nuclease resistance and biocompatibility. & [95; 96; 97] \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{6} & Uniform-sized amino-modified silica & \multirow{3}{*}{Sensor} & Detection of breast cancer cells at early apoptosis & [88] \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{7} & \multirow{3}{*}{Au-Pd} & \multirow{3}{*}{Cathode catalysts} & The core-shell Au-Pd nanoparticles could be used in MFCs as a good alternative to the & \multirow{3}{*}{[98]} \\  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{8} & Dual-Functionalized Core-Shell Fluorescent Microspheres & Vector & Far-red-labeled microspheres are ideal candidates for in vitro, cellular delivery of proteins. & [99] \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \multirow{3}{*}{9} & AgNPs@CeO\({}_{2}\) & \multirow{3}{*}{Nanocatalysts} & Catalyze the chemoselective reduction of unsaturated aldehydes to the corresponding unsaturated alcohols with H\({}_{2}\) & [100] \\ \cline{1-1} \cline{3-4}  & & & & \\ \hline \(10\) & Au-Ag & Parasitology & Antileishman Activity & [38] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Some applications of core shell nanoparticle in various scientific disciplines. of life for the world's population in the future. Greener and sustainable synthetic methods can reduce environmental pollution to some extent, while attaining economic growth via green chemistry. The importance and necessity of future progress in core-shell NPs encourages us to put forth the greener synthesis possibilities for core-shell NPs. We hope that some active researchers may feel stimulated to explore the use of this class of hybrid core-shell NPs instead of single NPs.