TABLE 4.

Troubleshooting table.

Step	Problem	Possible reason	Solution
1A(iv)	Gold nanoparticle aggregation	The injection speed for the polymer solution is too high	Add the solution at a speed of 50 μl/min, and sonicate the solution for 1 h after the addition. The glass bottle must be cleaned with aqua regia for 2 h and with DI water three times
1A(v)	Polymer precipitation on the glass bottom	The volume of AuNP solution is too small	The volume of the AuNP solution should be >4 ml
1A(vi)	AuNPs aggregate, and the solution color changes to blue	The centrifugation speed is too high or the centrifugation time is too long	The centrifuge speed cannot be >12,000g, and the centrifugation time cannot be >20 min. Sonication can be used to assist the dispersion of the AuNPs
1B(v)	The solution color changes to blue	The air in the glass reaction bottle is not completely removed, as shown in Figure 2c	Make sure that the glass reaction bottle is tightly capped, or change to a new cap
1C(vi)	AuNRs are not dispersed well	The reaction temperature is too low or the solution was not sonicated during the reaction process	Adjust the reaction temperature to 40 °C to initiate the polymerization of LA. The reaction bottle should be sonicated for 1 min every 10 min during the first 1 h of the reaction
2D(iv)	The sample cannot be removed from the tube	The centrifugation speed is too low, and the sample adheres to the tube wall	Increase the centrifugation speed and the time to precipitate the sample to the bottom of the centrifuge tube
5	The solution is not clear	Vesicles are not formed, or the sonication time is not long enough	Shake the bottle during the sonication. If the film is still on the wall of the glass bottle after 2 min of sonication, the water should be removed completely. Add 5 μl of chloroform to the glass bottle to rinse the film, followed by 1 ml of water and sonication